It isn't often the Embassy of the People's Republic of China opens its doors for a party, but it did the other evening to lionize the cast and crew of the touring Peking Opera Theatre Company after one of its KenCen performances.

The artistry of their silken, exquisitely embroidered costumes and the superb coordination of the players in their interplay of motion, stylized choreography, acrobatics, martial arts and wondrous Oriental posturing, can only result in enormous let-down when the players are party-met in Mao suits, T-shirts and mismatched ensenbles of every description.

The embassy is a former Connecticut Avenue hotel the PRC bought for its U.S. headquarters, and for good reason: Everybody from the PRC lives right there on the premises -- wives, too. But the kids are left at home for relatives to raise in the PRC way, and reunions occur every couple of years.

There wasn't an invited soul not thrilled to get in the doors, and all fell to like locusts over the several tables of Chinese goodies. And drinks, too . . . lined up as at an RFK concession stand . . . Big Orange, Coke, Chinese beer, several kinds of PRC wine.

Martin was finishing up an obviously devastating story with the following line . . . "And so Muskie said to him, "Hat do you think of the Far Eastern position?' . . . and he answered, 'well, I like it, but Nancy doesn't.'"

Librarian of Congress Dan Boorstin and Ruth were introduced to the official interpreter for the company, Gerald L. Wen of International Creative Management Artisits, the sponsoring U.S. tour arrangers. Wen, marvelously articulate, patiently wove questions and answers to and from the players.

Li Yuanchun, who had played the "Monkey King" role, joined the Peking Opera at age 7 and, like most of the other members, was literally raise in this millieu, rather like the Imperial Russian ballet schools. By age 12 he was ready for this super-demanding role, which tests physical coordination and acting skills to the limit.

Lee Lamont, ICM booking coordinator, says there hasn't been the least fear of any company member's defection while in the U.S., because "these people lead a very privileged life in China. They are special, even set apart, cared for in every way. There is no reason for discontentment and no reason to comtemplate defection."

Lee told of the tour, which has already played New York, Philly and New Jersey, and will go on to Kansas City, Los Angeles, San Francisco, Louisville, Minneapolis, Chicago and Boston after Washington. Everywhere they go it's a sellout.

The King Richard of Olde England currently trodding the KenCen boards hasn't been receiving raves, but another "King Richard" will be receiving nothing-else-but on Sept. 16, when stars will fall from everywhere to honor The Washington Post's Drama Critic Emeritus, Richard Coe.

American theater's reigning queen, Helen Hayes, will be honorary chairman.

Joining her in the KC atrium for the New Playwright's Theatre of Washington's "Salute to Richard Coe" will be Joan Fontaine, Jerome Lawrence, New York producers Richard Barr, Start Ostrow, Nelle Nugent and Lix McCann and John Eaton.

Joseph Papp, Broadway producer-angel of the NPT, will present Richard with the inaugural edition of the Richard L. Coe Award, in the future to recognize a "significant contribution to the development of original material for the theater."

It's fast becoming a department stor-party-society. Halls don't get hired anymore . . . everyone gets gussied up and decends on a posh store, where one sips an d sups among the shoes, lingers in ladies lingerie, makes conquests among the cold cream jars, with barmen knee deep in Louis Vuitton and Gucci bags.

There has to be a "Cause" and a "Star," and at Saks Fifth Avenue the other night the former was the Museum of African Art and the latter was Mary McFadden, the designer who's pleated more cloth than a filt factory.

But was bereft of pleats. Usually she's wrapped like a fluted column, but there she stood near the entrance, pale and white as moonlight, gowned in drifty print chiffon that cascaded all over the floor.

She does this . . . her formals mopping up the floor . . . but why not? When one owns the font from which all McFadden originals flow, one can do as one jolly well cares to . . . right?

There was another look that evening no tried to duplicate . . . Estee Seward's hairdo. She had wrapped her blond locks around three long sticks bound with satin ribbons, giving her a Sputnik look. She and Bob Shaeffer are Designs and Designers Ltd. and did the Thai orchids, birds of paradise and lilies from holland around which folks such as Sen. Ted and Phyllis Moss, Karen Hirschberg and Frank Vaccareally congregated.

Karen is one of THE most enviable personages we've run into in ages. She's been with channel 9 as a producer for lo these many, but that day had become "a dropout . . . I quit and bought one of those Eastern Arlines $600 tickets, and I'm going to travel in the U.S. 'til it expires, living out my fantasies."

Please go on!"Well, first I want to travel, like I said . . . then bartend at Clyde's in Georgetown . . . then be president of the United States . . . then go to law school." She welcomes suggestions for her future, which should be rosy, considering her looks and brains . . . and courage.

African Museum director Warren Robbins, in introducing the designer, called Mary "a visual historian. She studies and stores the cultures of mankind and then they come forth in her designs."

Her "Spanish Collection" this season, she says, is inspired by Goya and Valesquez, with the sumptuous silks and pleats coming forth in Joan Crawfordish modes, with bed-slat shoulder lines.

The museum connection was a natural, for Mary live in South Africa in the '60s, as editor of that country's Vogue . . . then on to Rhodesia, and was very much into the arts of all Africa.

For that many women to approve of something . . . anything . . . is a phenomenon -- no, a miracle!

But that's what happened when Patti Matson, ABC vice president for planning, brought "The Women's Room," a made-for-tv-movie, to the Sheraton-Carlton to do a private screening for Washington's Doing-Thinking Women.

A terrace reception brought the ladies and a few men together for nibbles and drinks. Hodding Carter, that Mississippi Delta-accented gent, was squiring wife Patricia Derian, still at State as assistant secretary of Human Rights and Humanitarian Affairs, and he does look as though he's totally enjoying a more relaxed life sytle.

Other males were Shaun Sheehan, senior v.p. of the National Association of Boradcasters; Vic Kamber, former AFL-CIO lobbyist now doing his own p.r.; Frank Scott, v.p. and general manager of radio for WRC-NBC; Ron Essen and Ken Dameron, Bill Proxmire's special assistant.

But it was Ladies' Night in the "Women's Room" and the stars were Lee Remmick, Patty Duke Astin and Colleen Dewhurst (unfortunately present only on the screen) in ABC's adaptation of Marilyn French's book about wives in the '50s and their crusade of independence into the '70s.

As Patti said, "This is not a movie to relax with . . . it is to provide thought," . . . as Remmick lives through mountains and crags of unplanned babies, formulas, cries in the night, tons of wet diapers, a student/intern/doctor husband who, of course, feels neglected and put-upon; then the expected "who in the hell AM I?" inner scream for help; then, also of course, the sure-to-come late-thirties divorce.

Remmick's best line: "There are many ways to destroy a woman. You don't have to rape her or kill her. You just have to marry her and put her to work for $35 a week."

Before the rather triumphant ending, many emotional responses came forth from females such as . . . Marguerite Beck-Rex, Sue Huhn, Harriet Matthews of NARAL; Jani Stevens, White House military office; Francie Barnard, Kenedy for President committee; Irene Tinker, Equity Policy Center; Ronna Freiberg, deputy director of research, Carter-Mondale committee;

Betsy Ashton, commentator WJLA-ABC-TV; Fran Paris, legislative assistant to Sen. Chaffee; White Houser Esther Peterson; Kathy Cade, Mrs. Carter's staff; Maria Downs, Reagan campaign staff; Evelyn Small, congressional relations, White House.