With red roses and "double happiness" badges pinned to their formal Mao suits, 40 young Chinese burst through the swinging doors into a hail of confetti. Two at a time, they sashayed past applauding guests and stood behind long tables in the center of the room.

The collective marriage ceremony of Peking's General Post Office had promptly begun at 9:30 a.m. in the fourth-floor auditorium.

Officiating at this new and unusual Chinese marriage rite was a fireplug-shaped man with the personality of a TV game show host. Standing at mock-military attention, he barked orders through a microphone.

"Turn and bow to the leaders at the head table," he said, nodding at the post office cadres behind him. "Turn to your guests and bow. Turn left. Turn right. Bow again to your guests. Now husband and wife face each other. Bow once for mutual love. Bow a second time for austerity. A third bow for mutual progress."

Amid giggles from the guests, the couples sat down and began rummaging through plastic bags of hard candy (an even number in each bag for good luck) and bowls of cigarettes and peanuts placed on the white tablecloths. One by one, they jumped up and flung the goodies at their family and friends. Some of them pranced over to the officials' table, the grooms plugging cigarettes into the mouths of amused cadres while the brides lit them.

There were the requisite speeches by the Youth League secretary. There was an accordion solo by a post office library clerk and a medley of family planning songs crooned by a letter sorter. There were photo albums given as gifts. And finally, at 10:10 a.m., there were the golden words that made it all official.

"The marriage ceremony is over," announced the master of ceremonies, jovially offering his good wishes to the newlyweds.

The 20 couples left the Peking general post office as man and wife, having chosen the latest communist fashion to observe the olders of Chinese customs.

Although such mass ceremonies are being pushed by communist elders as good alternatives to lavish private parties, they remain quite rare in a society where marriage still is regarded as "unofficial" until a traditional banquet is held for family and friends.

Most Chinese today get legally married simply by registering at government storefronts. They continue to live apart, however, until they can afford to host a party often costing the newlywed couple more than their combined yearly salaries. The banquets usually last 24 hours and feature the kind of traditional marriage rituals that the communist leadership long ago branded as "feudalistic" and bourgeois.

In large cities such as Peking and Shanghai, young couples have adapted centuries-old practices to modern times. The custom of carrying the bride to her new home in a sedan chair has been modified by renting a cab decorated with colorful streamers and the big red characters meaning "double happiness" that are seen everywhere on the wedding day.

Wedding customs die even harder in China's vast countryside, where 80 percent of its people live. When the big day arrives, firecrackers are exploded to scare off ghosts and evil spirits. Brides still wash the feet of their new mothers-in-law as a sign of respect and eat the head of a chicken to demonstrate ability to handle household affairs. Some couples bow to the family's ancestral shrine.

The old practice of hiring servants to parade through town with the bride's dowry in red carved boxes carried on bamboo poles lives with slight variations. dAt a recent ceremony in northwestern Liaoning Province, the bride's family carried a TV set, large tape recorder and radio console as a procession of relatives, friends and a musical bank followed behind, snarling local traffic for hours, according to new reports.

As the ultimate arbiter of public tastes, the Communist Party has tried for three decades to stamp out marriage customs it deems to be inconsistent with socialist morality and frugality. After outlawing bride sales, arranged marriages and commerical matchmaking, the party promulgated regulations for wedding ceremonies know as "The Four Don'ts" -- don't invite guests; don't accept gifts; don't notify friends and don't let matrimonial plans distract you from work.

When Chinese treated this edict with the disdain they reserve for most loosely enforced regulations, the party last year revived the concept of collective weddings that were popular among communist guerrilla fighters holed up in the mountain redoubt of Yenan in the 1930s and 1940s.

The chief hope for these group sessions is that they incorporate some traditional rituals, such as bowing to parents, while upholding communist ideals of simplicity. They also are designed to eliminate much of the superstition and commercialism that still touches most Chinese marriages.

The date of the ceremony is chosen by the sponsoring work unit, thus removing the pressure couples feel to pick a "lucky day." Although most private weddings are scheduled for national holidays to take advantage of extra vacation time, rural couples often consult fortunetellers for the most fortunitous day. Last spring in the Manchurian city of Harbin, more than 4,000 couples married on April 26 after it was discovered that this "lucky day" on the solar calendar corresponded with an equally lucky day on the lunar calendar.

Since collective ceremonies are held in public places, they free couples from the financial burden of furnishing a home for the wedding party. Before consenting to marriage, most women insist on a minimum of furnishings to "show face" at the banquet. The standard demand of brides in cities these days is "seven machines and a tic-toc plus 53 legs" (appliances, a clock and furniture).

The simple public affairs are also designed to give young couples more independence from their parents, sparing the would-be groom from the extortionate set of fees that many rural families still demand for the right to become engaged to and then marry their daughters.

According to Chinese news reports, a young man in the countryside may be required to pay "interview money" for his first meeting with the girl's family, "face money" to make him look good in the eyes of his potential in-laws, "birth pang money" to compensate the girl's mother for the pain of giving birth to her, "sedan chair money" to pay for the girl's leaving her home for the groom's and "door packets" to pay for the girl to actually cross the threshold into her new home.

Despite official efforts to discourage such "gold-digging" marriages and other old-fashioned practices, the strength of tradition has kept collective weddings from gaining much ground in the conservative countryside.

In the big cities, however, the idea has gained some currency among couples looking for a cheap and easy way to legitimize their marriages and among ambitious young people trying to curry favor with the communist bosses. Some couples are attracted by the subsidized honeymoon trip the government offers after the ceremony.

At the Peking General Post Office ceremony, Li Gaozhao and Zhao Yuhua were one of 20 couples formalizing their maggiage. They met four years ago at the post office and got legally married last June. But they continued to live with their respective parents until their workplace held its first collective wedding May 1.

After planning a private cermony, they decided to save the money and time by joining their colleagues at the collective wedding. Except for the new suit each bought, their only expense was $35 covering costs of the simple service and the train trip to the honeymoon spot at Beidaibe seaside resort.

"As young people of the party, we should follow the practice of frugality," said the bride, Zhao, 25, a postal illustrator.

Her new husband, Li, 26, a post office maintenance worker, offered a more traditional view.

"Since we registered for marriage last June, we lived apart and only saw each other once a week. It was a time for preparations, to ask our leaders for a room and buy some furniture. It was permitted [by law] to have sexual relations, but that wasn't the case with us. In China the custom is to have the ceremony before you begin to live together.

"Now everything is proper."