BEIJING, JULY 16 -- China has opened negotiations with the Soviet Union on the possible purchase of Soviet military technology for the first time since the two Communist giants entered into a war of words three decades ago, according to Western diplomats in Beijing.

China's proposed acquisition of Soviet arms technology follows a historic summit meeting that brought Soviet leader Mikhail Gorbachev here in May 1989. That meeting, overshadowed at the time by a student-led occupation of Beijing's Tiananmen Square, formally ended a protracted ideological battle between the two nations over the direction of world socialism.

Western diplomats said the arms-sales negotiations were initiated last month by Liu Huaqing, vice chairman of the Chinese Communist Party's central military commission. Liu made a two-week visit to the Soviet Union ending in mid-June as head of a delegation that included Maj. Gen. Shen Rongjun, vice minister of the state commission for science, technology and industry for national defense.

A Chinese source with military connections in Beijing confirmed that talks were initiated but could provide no details. China rarely comments officially on arms sales or weapons technology deals.

Western diplomats said that the Chinese have shown a particular interest in acquiring Soviet aviation technology. The United States had a $500 million agreement with China to modernize its F-8 interceptor planes, but Beijing canceled the deal earlier this year when the cost of the technology skyrocketed.

A Western military analyst said that China wants to gain access to Soviet technology in part because Western nations suspended all deliveries of military equipment to China after the Chinese army crushed the student-led democracy movement here in June 1989. "Why shouldn't we do it?" said a Chinese source with military connections. "The West cut us off."

It is not clear what the Soviet reaction has been so far to its largest neighbor's interest in upgrading its military technology. Soviet Embassy officials in Beijing declined to comment.

Western diplomats said that the Soviets, who are now reducing their military forces in Europe, might have an interest in selling surplus aircraft and aviation equipment to China. But they said the Soviets would likely be cautious in delivering military technology or equipment to Beijing because they still consider China to be a potential long-term threat, despite the current detente.

At the same time, Beijing sources said, Chinese military officers still designate the Soviet Union as the main military threat. For this reason, Western diplomats do not appear to be particularly alarmed by the Sino-Soviet technology talks.

But even if China and the Soviet Union agreed only to a limited transfer of Soviet military technology to China, it would be a remarkable development, considering the hostility that has long divided the two nations.

China has a surplus of light industrial goods and might seek to barter such goods for Soviet military equipment, the diplomats said. Barter trade would greatly reduce the cost of military technology for the Chinese government, which has been struggling with the effects of an economic austerity program and is trying to conserve its hard currency reserves.

The Chinese source with military connections suggested that the Soviets also could assist China with aircraft carrier technology. China has no carriers, but Chinese technicians have been studying the possibility of building medium-size carriers for several years.

The Chinese also have not yet developed or purchased aircraft capable of making carrier landings. And they could use assistance in developing electronics for the F-8 interceptor and in acquiring an air-to-air refueling capability for fighter aircraft.

Relations between China and the Soviet Union reached a low point in the early 1960s when Moscow withdrew technical experts from China, and border disputes led to bloody skirmishes in 1969 between Chinese and Soviet troops along their common border.

In recent years, the two sides have made progress toward settling the border conflict, and the Soviet Union has withdrawn thousands of troops from Mongolia, a vast Soviet-allied nation bordering northern China.

But despite the rapprochement, the Chinese leadership appears to be deeply suspicious of political changes undertaken by Soviet President Mikhail Gorbachev, although it has chosen not to publicize its criticisms. Instead, the Chinese have taken a pragmatic course, emphasizing the benefits that can be gained from an easing of Sino-Soviet tensions.

A Chinese source said the Beijing government has an equally pragmatic, but secret, relationship with Israel, which includes the transfer of Israeli defense technology to China. But he said this relationship is limited by a Chinese fear of offending Arab nations.

The source said the Chinese military wanted to push ahead more vigorously with their Israeli connection but that the Foreign Ministry has tried to limit the relationship. He said the main Israeli connection with China was in the field of aviation, with Israel helping to design and equip a new Chinese fighter plane with technology from its cancelled Lavi warplane project.