BEIJING, SEPT. 14 -- China is hoping that its cooperation with the West in the Persian Gulf crisis and in efforts to end the Cambodian war will lead to an easing of sanctions imposed by the United States and other Western countries after the army crackdown on demonstrations for democracy 15 months ago, according to diplomats and other analysts.

Although China has additional motives for lining up with the West on the Persian Gulf and Cambodia, "Obviously, it's very much in their minds that good things are expected to accrue to them from taking these correct positions," said one Western diplomat.

Some diplomats said that if Beijing continues to play a constructive international role, the sanctions could be lifted by the end of the year. The sanctions, imposed after the army massacre of Chinese protesters in Beijing in June 1989, included suspension of loans and a ban on high-level official contacts, and U.S. legislators considered dropping China's most-favored-nation trade status, which extends to Beijing certain trade privileges.

While accusing the West of interfering in its internal affairs by imposing the sanctions, Beijing has taken some conciliatory steps in the international arena.

China, which has backed a three-party Cambodian resistance coalition that includes the Khmer Rouge, played a constructive role on the issue ever since the other four permanent members of the U.N. Security Council -- United States, Soviet Union, Great Britain and France -- agreed nine months ago to start talks on a U.N. peace plan to end the 11-year war.

The talks resulted in a comprehensive political plan for Cambodia that was announced by the five powers last month and was agreed to by the four warring Cambodian factions this week. China was believed to have pressured its Khmer Rouge allies to make concessions that paved the way for the agreement.

In the Persian Gulf, China moved quickly after Iraq's invasion of Kuwait on Aug. 2 to halt arms sales to Baghdad, and it supported all of the U.S.-led resolutions in the United Nations Security Council, including one approving the use of military force to support the embargo against Iraq.

The Chinese took such actions, according to diplomats and Chinese sources, because Beijing's desire to improve its international image and its relations with the West was more important than preserving relations with Iraq. In addition, China this summer established relations with Saudi Arabia for the first time and did not want to risk tarnishing them by siding with Baghdad.

The Persian Gulf crisis has also served to shift the focus of world outrage away from Beijing.

"Before the Persian Gulf, China was regarded as a bad country, but then a worse guy appeared: {Iraqi President} Saddam Hussein," said one Asian diplomat. China is known to take its role as a permanent member of the Security Council seriously, and the gulf crisis provided Chinese leaders an opportunity to act in a responsible fashion, this diplomat said.

Diplomats said there will be several opportunities for Western countries to discuss the lifting of sanctions against China in the coming months, including at the annual meetings of the U.N. General Assembly in New York and the International Monetary Fund in Washington. "The general atmosphere is going in the direction of the West easing sanctions," the Asian diplomat said.

In recent months, there has appeared to be a slight warming in the Western attitude toward Beijing. British Foreign Office official Francis Maude was in Beijing at the end of July, and Australian Trade Minister Neal Blewett and New Zealand Minister for Agriculture and Fisheries Jim Sutton recently concluded visits here. Shortly after the Iraqi invasion, U.S. Assistant Secretary of State Richard Solomon visited to persuade China to stop arms sales to Iraq.

From the U.S. point of view, "the Chinese have performed quite well in Iraq-Kuwait and have been constructive in Cambodia," said one American diplomat. "If China continues to act in this way, one would anticipate a softening of the mood in the U.S. Congress."

Already, the move in Congress to link renewal of China's most-favored-nation trade status to an improvement in Beijing's human rights record here appears to be losing steam, according to diplomats and business executives. In addition, with attention focused on the gulf crisis, China is likely to benefit from Washington's tendency to divide the world into "those who are with us {on the gulf issue} and those who aren't," the diplomat said.