In an unprecedented move, a Chinese bricklayer who has spent four years searching for the man he says is his American father has been granted permission to come to the United States, an Immigration and Naturalization Service spokesman said today.

Zheng Lianqun, 34, has been granted "humanitarian parole" after an extraordinary search during which he buttonholed nearly every American he could find in Peking, received nationwide publicity in the United States and finally made a daring escape from China to Hong Kong.

The tall, freckle-faced, light-skinned Zheng is expected to be able to stay in the United States, a triumphant ending to an effort to reach what he considers his native land armed with nothing but persistence, charm and an unusual story of being abandoned in China in 1947. He won the official support of Rep. Patricia Schroeder (D-Colo.) after an interview at Hong Kong's Victoria Prison, and has received backing from other lawmakers as well.

"You can't help but be overwhelmed by his spirit," Schroeder said of Zheng, whom she met in Hong Kong, while Hong Kong authorities were preparing to ship him back to China. "When you see him, there is no question that he is part American." Immigration authorities "kept telling us it's a bad precedent," she said, but along with Sens. John Glenn (D-Ohio) and Walter D. Huddleston (D-Ky.) she asked that an exception be made.

The decision to admit Zheng, who is still in prison awaiting completion of paperwork, comes as a relief to State Department officials who have conducted several fruitless efforts to find documentary support for his story. His illegal trip to Hong Kong made them particularly uncomfortable, for Hong Kong law now requires all illegal immigrants to be sent back. Forcing a man with such strikingly western features back across the border after his American connections had severely hurt his chances for a successful life in China would have been, in the words of one official, "a public relations disaster."

Zheng said his father, an American Marine named George Lewis or Louis George, married his mother, a Tianjin millworker named Li Shuzhen, in 1946. When his mother left to join her husband in San Diego in 1947, she felt her 3-month-old baby was too young to travel and arranged to send for him later, Zheng said. But after the communist victory in China and the Korean war, Zheng said, his remaining relatives burned all evidence of their American connection.

Zheng said in an interview in 1979 in Peking that he was not told that he had an American father until 1972, when President Nixon visited Peking and official U.S.-China relations resumed. In 1977, he began a concerted effort to reach the United States and find his parents, writing dozens of letters to U.S. officials, visiting the U.S. Embassy in Peking many times and selling his blood at least nine times to various Chinese hospitals to finance his search.

After he launched his search, Zheng was denied admission to the Chinese air force and was no longer allowed to read special communist party bulletins circulated in his construction company because of his assumed but unproved foreign connection.

He continued to meet any new American official visitors to Peking with a winning smile and a charm that even got him past the security guards at the Peking Hotel, who usually stop all unauthorized Chinese. His search apparently became such an obsession that he tended to forget his wife and small child back in Tianjin. In 1980, his wife wrote to a Peking-based American reporter asking if he could find her husband and tell him to come home because their second child was about to be born.

In May, 1981, Zheng reached Hong Kong and went into hiding. According to Schroeder, U.S. consular official Virginia Carson helped persuade Zheng to turn himself in to the Hong Kong authorities and then persuaded the same authorities to hold him until his case could be considered further in Washington.

Jack Reynolds, the correspondent for NBC in Hong Kong, was particularly active on Zheng's behalf. Reynolds contacted Kee Chang, a former NBC employe now living in Dover, Del., to see if Chang would be Zheng's financial sponsor. Chang, a Vietnamese of Chinese descent who worked for NBC in Saigon, now has two restaurants in Delaware called the "Orient Express."

"I realized how difficult it is to be a refugee like that," Chang said. He agreed to sponsor Zheng and give him a job, an essential requirement before Zheng could be admitted to the country. Zheng would be able to send for his wife and children after establishing residency here.

Authorities in Hong Kong said today that Zheng will be allowed to leave as soon as U.S. authorities produce an airline ticket for him.

Zheng is expected to continue his search for his parents and while officials do not have great hope he will succeed, they consider him lucky to have made it here at all. "Any other case would have died of red tape in the bureaucracy," said Andrea Pamfilis, Schroeder's legislative assistant who worked on the case, "but the difference was a couple of people met him and really believed him."