Ruth Gordon, an actress and writer whose perpetual energies seemed to defy time, died yesterday at her summer home in Edgartown, Mass. She was 88 years old.

In those years - the last 70 of them in and around the worlds of stage, screen, television and letters - Miss Gordon manifested a fearsome will and an insatiable appetite for things new. She was a seaman's daughter, and she never tired of exploration or conquest.

''Pan me, don't give me the part, publish everybody's book but this one and I will still make it!'' Miss Gordon wrote in ''My Side,'' her autobiography. ''Why? Because I believe I will. If you believe, then you hang on. If you believe, it means you've got imagination, you don't need stuff thrown out for you in a blueprint, you don't face facts - what can stop you? If I don't make it today, I'll come in tomorrow.''

Garson Kanin, Miss Gordon's husband of 43 years, said that even her last day of life was typically full, with walks, talks, errands and a morning of work on a new play. She made her last public appearance only two weeks ago - at a benefit showing of the film ''Harold and Maude'' - and she had recently finished acting in four films. In one of them, characteristically enough, Miss Gordon insisted on doing her own motorcycle stunts.

''She had a great gift for living the moment,'' said Glenn Close, who co-starred with Miss Gordon in ''Maxie,'' one of her last films, ''and it kept her ageless.''

'A Total Original'

Helen Hayes, who was one of Miss Gordon's closest friends, said: ''She was a total original. There was no one else like her, and no one had the courage to try to imitate her.''

Miss Gordon's stage credits included Nora in ''A Doll's House'' and Dolly Levi in the original ''The Matchmaker.'' Screen audiences know her best from her roles in ''Harold and Maude'' and ''Rosemary's Baby'' - for which she won an Academy Award - and as the co-author with Mr. Kanin of the Spencer Tracy-Katharine Hepburn classics ''Pat and Mike'' and ''Adam's Rib.'' She wrote two books, ''Myself Among Others'' and ''My Side,'' as well as three plays, one of them the autobiographical ''The Actress.'' She won an Emmy Award for a 1979 appearance on the television show ''Taxi.''

Miss Gordon was one of those rare New York theater people who were performers, intellectuals and fixtures in the social firmament. She was a favorite of Alexander Woolcott and the members of the Round Table at the Algonquin Hotel. Her friends ranged from Thornton Wilder to Mia Farrow. She and Mr. Kanin maintained not only a Central Park South apartment but also a studio in Carnegie Hall.

''There was such an elegance about her, such a brilliance about her,'' recalled Bud Cort, who co-starred with Miss Gordon in ''Harold and Maude.'' ''I'd leave lunch with her feeling like I'd been with a statesman, a diplomat.''

Yet for all her acclaim and achievement, Miss Gordon still relished being recognized on the street. ''I don't care who remembers me, or for what,'' she said in an interview last year. ''I love it. I never get over it. I never get used to it.''

Hometown Girl

Miss Gordon also held tenaciously to her hometown of Quincy, Mass. Although she left Quincy more than 70 years ago as a stagestruck girl bound for Broadway, she read the local newspaper and maintained friends there her entire life. Last November, Quincy held a Ruth Gordon Day and dedicated an amphitheater in her name.

''I'm the first person in my family to have a theater named for her,'' Miss Gordon said at the ceremony. ''It took a long time. I started toward this 88 years, 11 days and five and a half hours ago. I never face the facts. I never listen to good advice. I'm a slow starter but I get there.''

Ruth Gordon Jones was born in the Wollaston section of Quincy on Oct. 30, 1896. Her father, Clinton Jones, was a sea captain and later a factory worker. He hoped his daughter would grow up to be a physical-education teacher.

''But I hated all those serge bloomers and dumbbells and Indian clubs,'' Miss Gordon recalled last year. ''I wanted to do something a little more sexy than that.''

Saw First Musical

She realized what it was when she went to Boston to see a musical entitled ''The Pink Lady.''

''Hazel Dawn was singing, 'Dream, dream, dream and forget/Care, pain and useless regret,' '' she recalled years later. ''That was the moment I knew I wanted to be an actress.''

With the resolve that typified her entire career, the 18-year-old left for New York. Her father gave her the money for one year's tuition to the American Academy of Dramatic Arts, plus $50 in spending money and his old spyglass.

''He told me I could hock it if I needed money,'' she later recounted. ''He said, 'If you're going to be an actress, you'll be in and out of hock shops all your life.' Well, I hocked plenty of things, but never that spyglass.''

Miss Gordon needed more than money to survive her first years in New York. After one term in drama school, she was informed she had no talent and was told to leave. She did make her Broadway debut in 1915, as Nibs in ''Peter Pan,'' but her first starring role, in Booth Tarkington's ''Seventeen,'' received withering reviews. Heywood Broun, writing in The New York Tribune, said: ''Anyone who looks like that and acts like that must get off the stage.''

Naturally, Miss Gordon did not. She took whatever work she could find, in New York or in the road companies of Broadway shows. In the one concession to her physical limitations, she had a Chicago doctor break and reset both her knees to correct her bowlegged stature. She strengthened her voice and avidly researched every role she played, developing a wide range.

Her turning point arrived with ''Holding Helen'' in 1925 and ''Saturday's Children'' two years later. Then - after a decade of steady and well-received work in America and a stint as the first American actress to perform with England's Old Vic Company -she burst into stardom in 1936 as Mattie Silver in ''Ethan Frome.'' Later the same season, she illustrated her diversity with a comic turn as Mrs. Pinchwife in the Restoration comedy ''The Country Wife.'' In 1937, she won praise as Nora in ''A Doll's House'' and in 1940 she turned to film, portraying Mary Todd Lincoln in ''Abe Lincoln in Illinois.''

Miss Gordon wed Mr. Kanin in the early 1940's, a marriage that was both personally and professionally fruitful. Her first marriage, to Gregory Kelly in 1918, ended after six years with his death. She also had a love affair with the producer Jed Harris, with whom she had her only child, a son, Jones Harris.

Miss Gordon and Mr. Kanin together wrote such successful screenplays as ''A Double Life,'' ''Adam's Rib'' and ''Pat and Mike.'' Her own hit plays were ''Over 21'' and ''Years Ago.'' She also continued her stage career with such roles as Natasha in the Katherine Cornell production of Chekhov's ''Three Sisters.''

Found a New Audience

But for 23 years, from 1943 to 1966, Miss Gordon did not act in a single film, partly because of her constant activity on other fronts. When Miss Gordon did return to film, however, she found an entirely new audience, moviegoers young enough to be her grandchildren. And that, Mr. Kanin recalled yesterday, brought her delight.

''Her great joy,'' he said, ''was hanging around young people. She was always very much involved in the new stuff. I remember when we went to see 'Hair' at a preview. Richard Rodgers was there and he walked out after the first act. So did David Merrick. All these Shubert executives left. But Ruth just went bananas. She thought it was just terrific. She went backstage to congratulate the cast and went back to see the show many, many times.''

Modern film audiences first discovered - or rediscovered - Miss Gordon as a witch in ''Rosemary's Baby'' in 1968. Accepting her Oscar for best supporting actress at the age of 72, and after so many years without film work, she remarked caustically, ''I can't tell you how encouraging a thing like this is.''

Shortly after ''Rosemary's Baby'' came roles in two films that built loyal cult followings. In ''Harold and Maude'' Miss Gordon portrayed a funeral groupie who falls in love with a young man intent on committing suicide. And in ''Where's Poppa'' she played the daffy mother who has for breakfast Lucky Charms cereal topped with Pepsi-Cola.

Played Clint Eastwood's Mother

Miss Gordon's other film roles included Clint Eastwood's acerbic mother in ''Every Which Way but Loose'' and in ''Any Which Way You Can.'' She also acted in four films that are now awaiting release: ''Maxie,'' ''Mugsy's Girls,'' ''Trouble at the Royal Rose'' and ''Voyage of the Rock Aliens.''

''She made such a show of vitality,'' Mr. Kanin said of her ceaseless pace. ''I could scarcely believe it myself.'' In her will, Miss Gordon instructed that there be neither a funeral nor a memorial service and specified that her body be cremated. ''I'll honor her wishes,'' Mr. Kanin said yesterday. ''I always did when she was alive.''

In addition to Mr. Kanin, Miss Gordon is survived by her son, Jones Harris, and a grandson, Jack Harris.

''It's awfully sad when the lights go out,'' Helen Hayes said yesterday. ''And this is one more dark spot in American theater, losing Ruth.