Politically, it wasn't what you'd expect to find in a White House occupied by Democrats: a bunch of elephants forming a receiving line.

Socially, it had to be one of the highlights of the White House Christmas season: 400 children from 89 foreign countries shaking the trunks of Babar and some of his elephant friends.

It all happened yeserday at the 17th annual White House Christmas party for diplomats' children, a tradition begun by former first lady Jacqueline Kennedy.

This year, under Rosalynn Carter, the event was also a birthday party for her 1-year-old granddaughter. Sarah Carter, a milestone duly acknowledged when everybody serenaded her with "Happy Birthday." Taking part were Sarah's aunt, Amy Carter; her brother Jason, 4; and her cousin, James Carter, almost 3.

First, though, came the show, the Washington debut of the Metropolitan Opera Ballet Company's production of Poulenc's "The Story of Babar, The Little Elephant." Decked out in dovegray costumes punctuated with oversized ears, tummies, feet and snouts, the 28-member company displayed a grace and agility seldom associated with Elephas maximus or his African cousin Loxodonta africana.

"Even New York hasn't seen it yet," said Anthony Bliss, executive director of the production, which is part of the ballet's expanded educational program begun last year by John Dexter. Dexter was there, as was James Levine, music director. Accompanying Bliss was his wife, Sally, a former dancer with the company, and their two sons, Marc, 11, and Tim, 9.

For the uninitiated, Babar is an engaging, if not exactly cuddly elephant orphaned at an early age by a trigger-happy hunter. Wandering into a big city, he is befriended by a wealthy benefactress. Eventually reunited with some cousins (one of whom he falls in love with), Babar finds the lure of the jungle irresistible and returns to marry cousin Celeste and to be crowned king.

If the ending was happy, there were moments between it and the beginning (the deaths of his mother and the elephant king) which might have warranted a few tears from a less sophisticated audience. None, however, were forthcoming from the crowd, aged 6 to 11, assembled in the East Room.

"I don't like to cry," said Hussam Nazer, 9, of Saudi Arabia, there with his sister, Aseel, 7, equally stoic.

What Hussan and others did like was the wedding, nuptials like no other, for which Celeste, the bride, chose a white lace (tent) dress; bridgegroom Babar voluminous red velvet, and the dromedary, one of the guests, what else but a camel's-hair suit.

"I liked your story," said Carolina Manhusen,6, of Sweden, rushing up to Werner Klemperer, the safari-suited narrator, over punch and cookies in the State Dining Room.

"Thank you, darling," replied Klemperer, better known to TV fans, perhaps, as Colonel Klink of "Hogan's Heroes" fame, planting a kiss on Carolina's cookie-crumbed cheek.

Yesterday's party was organized by The Hospitality and Information Service (THIS), a volunteer organization that assists diplomatic families, and was open to all requesting invitations by Dec. 11. Neither Iran nor Libya responded, a THIS spokeswoman said.

"The children of the Iranian charge d'affaires are too young," she said.

Although the children represented religious faiths other than Christianity, they responded with one somewhat tentative voice to Mrs. Carter's questioning, in her welcome, about what Christmas signified: "Love" and "Jesus Christ."

For his part, Hussam Nazer knew exactly who his hostess was.

"She's the president of America," he told a reporter.