When the Peking Opera opens its run at the Kennedy Center on Tuesday, Metropolitan Opera star Roberta Peters will be starting a concert tour of the People's Republic of China. "It's a happy coincidence rather than a formal exchange agreement," said Lee Lamont of ICM, the management agency that arranged both tours. "But we're very pleased that it worked out this way."

Peters, the first American opera star to tour the People's Republic of China, will visit the country for 12 days. Her itinerary and programs are not yet completely decided, but she will sing in at least three cities, including Peking and Shanghai, and give master classes at the Peking Conservatory. Bian Quing Zu, second secretary of the Chinese Embassy in Washington, who isin charge of cultural affairs, said that his government considers her visit "a great honor."

Peters will be traveling at the invitation and expense of the Chinese Performing Arts Agency, a branch of the Ministry of Culture. She plans to sing music of Mozart and Schubert, besides the operatic repertoire for which she is best known, and some American songs. "I am also learning a Chinese song -- phonetically, of course-- to sing at the end of each performance," she said. "I hope to have an interpreter with me on the stage to explain the songs before I sing them."

Negotiations for the tour began in Peking, when Sheldon Gold, president of ICM, was arranging for the American tour of the Peking Opera. "I met the Chinese ambassador last winter whenI sang at the State Department and we talked about my touring in China," Peters recalled at a press conference yesterday. "Then, a few weeks ago, a lovely, handwritten invitation arrived from the Chinese Embassy."

At the end of the conference, Patrick Hayes, president of the Washington Performing Arts Society and a longtime personal friend of Peters', said that the master classes she will give are even more significant than the song recitals. "After a performance, the audience goes home and you go back to your hotel, and the penetration is not so deep," he said. "But when you give master classes, when you help to affect the development of young singers, you are doing something essential and something with important long-term effects."

Peters will begin her 30th season at the Metropolitan Opera next season.