For two weeks now, Moscow's ballet world has been packing itself inside the great gold hall of the Bolshoi Theater to watch the first two rounds of this year's International Ballet Competition.

It is an audience to be reckoned with -- from the great prima ballerinas of the Bolshoi's past and members of its present-day establishment in the front rows, to the flocks of thin-shouldered dance students perched over the top balconies, to the ticket takers who slipped into the back of the upstairs boxes to peer critically at the dancers below.

"He worries too much," clucked one usher as she watched a young Polish dancer falter on stage. "And he's not very strong."

This year, as the competition -- held every four years -- winnowed out 24 finalists from the original 90 entries from 20 countries, the Bolshoi elite took its measure of the young talent on the world ballet scene. The two American entries, Maria Teresa Del Real with the Pittsburgh Ballet and Li Cunxin of the Houston Ballet, will be competing in the final round. Four years ago, Amanda McKerrow, then of the Washington Ballet, took the gold medal.

For the dancers, the applause here is the first test of their performance and emotionally, perhaps the most important. Although only one of several competitions on the international circuit, Moscow is considered the most prestigious and the most exacting.

"The audience here is more selective, more discerning than anywhere else," said Del Real, 22, whose strong performance in the second round drew perhaps the competition's warmest applause.

"They are really ballet lovers. It is fantastic the way they applaud."

Always polite, the Bolshoi audience responds with a sympathetic "tss" when a dancer slips, and gives a correct, if cool, hand of applause to the clumsiest of performances. But when they like a dancer, Moscow's expert ballet-goers hold little back.

The Soviet news agency Tass paid its tribute this week to the Bolshoi audience. In a short release on the competition, Tass said of the "Ballet devotees" at the Bolshoi: "They warmly applaud every successful performance and their assessment is always correct . . ."

The Bolshoi Theater this year is 209 years old. The Kirov, its great rival in Leningrad, this year celebrated its 250th birthday. Given their long tradition and their history of outstanding dancers, Russians in some ways have come to regard ballet as national property.

Not that they are crudely chauvinistic: witness the enthusiastic response this year to Del Real and her French partner, Pavlo Savoye, to Cunxin and other foreign favorites including Yukos Moarimoto of Japan, Julio Bocca of Argentina and Murei Maffre of France. All are in the final round, which starts Monday. The results will be announced Tuesday.

But underneath the obvious pleasure at the foreigners' achievement, one gets the sense that in the end, people here still feel that the best ballet dancers are born, trained and perform in the Soviet Union.

And so, there was little surprise when 12 of the 13 Soviet entries in the competition made the finals, which means that one out of every two finalists is a Soviet. (This year the junior division was eliminated, so all dancers ages 17 to 25 are entered in the same competition).

The decision by the 32 judges, of whom nine are Soviet, was met with some grumbling, but nothing too loud. The Soviet dancers this year, as always, are considered to be beautifully trained with the classic Russian style and poise: critics fault them basically for not being extraordinary.

Some are competing in the international competition for the second time, two of the Soviet finalists -- Kaye Kyrb and Vadim Pisarek -- last year won the Soviet national competition.

As in any field, ballet has its gossip, its politics and its networks. The overwhelming figure in Moscow is Yuri Grigorivich, artistic director of the Bolshoi and chairman of the jury. "That," noted one foreign ballet expert, "is a lot of power."

Soviet dominance in the ballet world is nothing new. What was new this year was the emergence of the People's Republic of China.

This was the first time that China enrolled its dancers in the Moscow Competition. That the Chinese came and have done well is taken here as a sign of both the political thaw between the two communist giants and of the maturation of Peking's Dance School.

According to dance experts, the Chinese have been enrolling in more and more competitions recently, as if to signal that they are now ready to go out on the world stage.

Of the seven Chinese dancers who came to Moscow, all made it into the second round and three to the finals -- not bad for a first show.

The Bolshoi audience took an intense interest in the Chinese dancers, watching closely to see the state of the art in Peking. The curiosity in the Chinese success is almost personal, since it was Soviet ballet masters who in the late 1950s founded the Peking Dance School and began training young Chinese dancers.

Many Soviets seeing Peking's young talent for the first time were struck by the dancers' figures -- their height, and long legs in particular. "For us, this is something interesting," said one Russian woman. "We thought the Chinese were short."

The Chinese were part of a larger far eastern contingent that did well in the early rounds. Five Japanese dancers made it into the second round, although none into the finals.

"Both the Japanese and the Chinese have made a forceful appearance this year," said Robert Joffrey of the Joffrey Ballet, who is here for the third time as a judge in the competition.

The Chinese challenge has particular poignance for Li Cunxin. Six year ago, he was finishing at the Peking Dance School when he got an invitation to study in Houston with Ben Stevenson, a former dancer with the Royal Ballet.

Cunxin fell in love with an American, married and stayed in Houston, causing a minor political scandal at the time.

Now he finds himself in Moscow, competing with his old classmates. When he performed in the second round last Saturday, the dancer ahead of him on the program was a fellow student who had gone with him to Houston in 1979.

Cunxin has been able to talk with his old friends here, but still, he says, it is as if "some kind of wall" still separated him from them.

Cunxin was 11 when recruiters from Peking came to his native city of Tsingtao looking for young talent. At the time, he says he barely knew what ballet was and certainly had no hankering to go into it: if anything he wanted to be in opera.

For 10 days, they checked him out -- for looks and physique -- and gave him tests to see how tall he would grow, to measure his flexibility and strength. He passed and became one of 40 children between the ages of 9 and 12 chosen that year to study at the Peking Dance School.

By the time Cunxin was enrolled, the Soviet ballet masters had left Peking but their influence remained, giving him a solid classical training. His was the first class to finish the school after the cultural revolution -- a factor he credits for the emergence on the world scene of his generation of Chinese dancers.

Cunxin made his biggest hit here with his performance to a piece choreographed by Stevenson to contemporary music, one of two sets required for Round 2.

He gave a supple and eloquent performance, despite an injury to his shoulder, which occurred the night of his first performance on the Bolshoi stage. That piece of bad luck was compounded by other falls here, although Cunxin obviously was able to recoup. "I have fallen five times in my career, and three times here," he said with a rueful laugh.

Cunxin's contemporary piece, unlike other selections which show off techniques, was more theatrical, involving interpretation and performed with great feeling. Some in the audience found it strange, but Maya Plisetskaya, one of the Bolshoi's most famous ballerinas, came to his dressing room to congratulate him. "She said it was art," said Cunxin. "To me, this was very thrilling."