China today said it is conducting scientific research with the United States on earthquakes but denied that the two nations were holding discussions aimed at cooperating to monitor Soviet underground nuclear tests.

Commenting on the issue for the second time in two weeks, a spokesman for China's Ministry of Foreign Affairs today denied that the two nations were conducting negotiations to install new seismic devices in China to monitor the tests.

A report in The Washington Post March 19, quoting administration and congressional sources in Washington, said negotiations were being conducted over a China-based facility. The negotiations were mentioned in the fiscal 1987 Department of Energy budget request.

According to the document, the seismic center in China would be similar to one installed in Norway and could help verify Soviet compliance with treaties that currently limit, and could eventually ban, underground nuclear tests. The budget document also said negotiations began with China in fiscal 1986 "on a cooperative effort to culminate in the installation of a regional seismic array" in China.

At a regular weekly news briefing, Foreign Ministry spokesman Ma Yuzhen today denied that discussions had taken place on the installation of seismic equipment to monitor underground tests.

A U.S. Embassy official here also said the Energy Department budget request was not accurate.

Concerning the reports of talks about monitoring Soviet tests, the official said, "there have been no discussions at all and no official presentation to the Chinese government on behalf of the American government."

He added, however, that a possible proposal concerning such monitoring "was under discussion within the U.S. government."