Peking — Vice-President George Bush's visit to Peking May 7 to 9 may mark a turning point in Chinese relations with the Reagan administration.
The word ''may'' is important, for the turning point is not visible now.
Indeed, some observers say the visit, for all the atmospherics of the Stars and Stripes fluttering from lampposts in Tian An Men Square, did not change the fundamental disagreement between Peking and Washington over American arms sales to Taiwan.
But the vice-president himself, in a pre-departure press conference May 9, took a determinedly optimistic stance. Both Chinese and American officials privately expressed satisfaction over the visit and its outcome.
There was no breakthrough. But a Chinese source suggested that Mr. Bush, having talked directly for more than two hours with Vice-Chairman Deng Xiaoping, and having met separately both with Premier Zhao Ziyang and Foreign Minister Huang Hua, could convey to President Reagan a first-hand impression of the basic Chinese position.
The US side is known to feel similarly pleased, even to sense the possibility of a compromise where there had been only deadlock before.
All Mr. Bush would say publicly was that he was going back to Washington with ''a few specific ideas.'' Actual negotiations on the arms sales issue have been and will continue to be conducted by Ambassador Arthur Hummel with his counterparts here in Peking. Presumably Mr. Hummel will receive new instructions once President Reagan has had a chance to digest the information and ideas Mr. Bush is taking back with him to Washington.
Letters from President Reagan to Mr. Deng, to Mr. Zhao, and to Chinese Communist Party Chairman Hu Yaobang, released at Mr. Bush's press conference May 9, suggest how Mr. Reagan hopes to reconcile two conflicting goals: to strengthen the strategic partnership with a new friend, China, against Soviet expansionism, while maintaining his commitment under the Taiwan Relations Act to continue supplying defensive arms to an old friend, Taiwan.
''The differences between us,'' Mr. Reagan noted in his letter to Premier Zhao, ''are rooted in the longstanding friendship between the American people and the Chinese people who live on Taiwan.''
He noted with appreciation Chinese policies toward Taiwan indicating the desire for a peaceful settlement, and then suggested that, ''in the context of progress toward a peaceful solution, there would naturally be a decrease in the need for arms by Taiwan.''
In his letters to Messrs. Deng and Hu, Mr. Reagan repeated a firm commitment to the principle of ''one China'' and said, ''We will not permit the unofficial relations between the American people and the people of Taiwan to weaken our commitment to this principle.''
The Chinese are known to oppose linking progress toward peacefully reunifying Taiwan with a decrease in US arms sales to the island. Some new formulation taking account of Chinese sensitivities may be worked out in Washington after Mr. Bush's return.
The bottom line, the line no American president can cross, is to scrap the Taiwan Relations Act and agree to an explicit cutoff date for arms sales to Taiwan. Mr. Bush has apparently given the Chinese a thorough explanation why this is not possible. He has in turn heard Mr. Deng's forceful presentation of the Chinese position that US arms sales to Taiwan infringe on China's sovereignty over Taiwan.
And, as all this went on, Mr. Bush told his press conference, he was ''thinking how the matter can be resolved - and I believe that the matter can be and will be resolved.''
Whether his optimism proves well-founded must await the results of his consultations with President Reagan and the Chinese response thereto. If a solution does emerge from what both sides admit is still a paper-thin margin of compromise, then the Bush visit can justifiably be characterized as a turning point.