United Nations, N.Y. — As China prepares to welcome Ronald Reagan, it remains determined to pursue an independent foreign policy. Globally, it means that while improving and stabilizing its relations with both the United States and the Soviet Union, China also intends to keep its distance from both of them. (China's balancing act, see Page 9.)
''Neither will it become again a de facto strategic ally of the US, as had been the case under Jimmy Carter, nor will it enter into a partnership with the USSR such as existed in the '50s,'' says a senior Asian diplomat familiar with Chinese thinking.
Regionally, an independent foreign policy means that China has decided to bank heavily on its relationship with Japan. China is depending on its historic reconciliation and a close partnership with its former rival.
Japanese Premier Yasuhiro Nakasone's successful trip to Peking in March strengthened that tie, which in many ways parallels the Franco-German reconciliation initiated by Charles de Gaulle and Konrad Adenauer.
''Japan and China together form a geopolitical entity powerful enough to be autonomous vis-a-vis both super-powers,'' says a longtime Asia-watcher.
A fourth round of Sino-Soviet political talks in Moscow concluded at the end of March. While no official statements were issued after the consultations, no breakthrough was achieved on political issues.
Various Soviet proposals aimed at circumventing China's ''three main obstacles to normalization'' were rejected. The Soviet Union did not make concessions regarding Vietnam's occupation of Kampuchea (Cambodia), its own occupation of Afghanistan, or its troops deployed along the Sino-Soviet border. China would like to see these troops moved back and reduced in number.
But the ''three obstacles'' have not stopped Sino-Soviet relations from improving in areas such as trade, science, culture, and sports. In this respect, the fourth round of Sino-Soviet talks has been successful, say diplomatic sources.
Two-way trade between the Chinese and Soviets jumped from $400 million in 1982 to $800 in '83 and is expected to reach $1.2 billion this year.
''China looks favorably on trade with the Soviet Union because it can be based on barter and because the Soviets are ideally suited to reequip and modernize the Soviet-built Chinese factories of the '50s,'' says a Western diplomat in Peking.
Last year, 30 Soviet students went to China and 30 Chinese students went to the Soviet Union. This year that number will climb to 100. And there will be more intensive scientific exchanges and more frequent visits of sports teams.
''Nothing better expresses both sides' desire to improve relations than the fact that China sent Wan Li, the vice-premier, to (Yuri) Andropov's funeral and that a Soviet vice-premier, Ivan Arkhipov, is expected in Peking next month, practically on the heels of Reagan,'' says a Chinese commentator.
No longer does Peking call Soviet leaders ''social imperialists'' or ''new czars.'' ''Soviet hegemonists'' and ''American imperialists'' are now put on the same scale. While China denounces Soviet policies in Afghanistan, Vietnam, and Mongolia, it criticizes US behavior in Central America, the Middle East, and southern Africa.
''China seeks to milk both cows (Soviet Union and the US),'' says one East European diplomat sarcastically.
''That is a very narrow view of China's intentions,'' says an Asian diplomat who watches China's foreign policy closely.
''In fact, China wants to avail itself of a vast array of political, military , and economic advantages and give itelf as much leverage as possible in its dealings with individual partners, large or small.''
Says a Chinese official: ''No one should be able to take us for granted.''
An Asian diplomat familiar with Chinese thinking explains, ''China is busy dating the nonaligned, the USSR, the United States. Let each of them believe that they have secretly won China's heart.
''The main thing is that this way China is not really committing itself to anyone. To extract itself from its economic backwardness, China needs time and to enjoy peaceful relations with all those who in some way can contribute to modernize China's economy.''