Beatrice Arthur is pleased to play an old-fashioned love story with Richard Kiley, although her view of it is anything but sentimental.

"It's like a geriatric Doris Day and Rock Hudson romance," she says of the ABC movie First Love (Sunday at 8 p.m., Ch. 4).She plays a widow who, a suitable time after the death of her husband, pulls out some yellowing letters she's saved for years and gets in touch with her high school sweetheart. To her astonishment, their old romance is rekindled.

"It's a very sweet love story," said Arthur. "We don't get into any of the problems of the world. People say, `Oh, it's never been done before, older people having a romance."'

Actually, it has been done before. Katharine Hepburn made several romantic movies at an age when most actresses are playing mothers or grandmothers.

"Over the weekend I was watching some Doris Day and Rock Hudson movie," Arthur said. "I said, `That's what we did."'

Besides Arthur and Kiley, the movie stars Joan Van Ark and Anne Francis. It was filmed in Los Angeles and in New York.

"When they first sent me the script for the movie I said it's too simple," she recalled. "It's too simplistic. Gil Cates said, `That's its charm. No one has acne, no one sweats.' He called it a fable. It's a fairy tale. It was such a pleasure to do.

"People keep telling me they're surprised to see me do this kind of a role. I guess it's because I wasn't the stern Maude or Dorothy. It's refreshing to read a script like this. So much of what you see is junk."

Arthur, who describes herself as one of the few actresses who doesn't dye her gray hair, stars as Dorothy in the NBC comedy hit "Golden Girls." She previously starred in "Maude."

At the time "First Love" airs, she will have just returned from London, where she and "Golden Girls" co-stars Betty White, Rue McClanahan and Estelle Getty were invited to put on a special show for a royal command performance.

Arthur was a Tony award-winning Broadway star, occasional feature film performer and a regular hand in George Gobel and Sid Caesar TV variety shows before Norman Lear brought her west to star as "Maude."

"People always judge you by what you did last," she said. "Dudley Moore said to me, `I didn't know you sang.' He didn't know me when I was in the musical theater on Broadway. In drama school I did classical roles, but it was hard to do classical roles on Broadway.

"I got a job singing in a nightclub. I took myself very seriously. Everyone was trying to sound like Lena Horne. Julius Monk was running the nightclub, and he said, `You're so tall and imposing, no one's going to take you seriously if you sing that your man's left you and you're going to throw yourself into the river."'

She never did comedy until "Three Penny Opera."

"I was hired as a singer," she said. "The audience laughed at one song. I was emoting, and I couldn't believe it was funny. Then I started to relax and after that comedy came easy for me."

She was first discovered by Lear in an off-Broadway revue in 1954. Five years later when Lear was doing a variety show with Gobel, he invited her to become a regular. "I couldn't get arrested in New York, so I came out here and did it for a while," she said. She was also a regular on "Caesar's Hour."

She won her Tony for her role as Vera Charles in "Mame." Angela Lansbury won a Tony for the title role. Arthur was in the movie version of "Mame," and in "That Kind of Woman" and "Lovers and Others Strangers."

Later, when Lear was doing "All in the Family" he invited her to do a guest role. She played Maude Findlay, Archie Bunker's liberal cousin. CBS took one look at it and signed her up for her own series. "They said, `Who is that girl?' By then I'd been around for 50 years."

"First Love" is the first time Arthur has worked with Kiley, who starred in NBC's "A Year in the Life."

In "New York, we all lived in Rockland County," she said. "Richard and I were neighbors. A picture we use in the movie is a photograph of Richard holding one of my sons 27 years ago."