China and the United States initialed an agreement today to facilitate trade as latest estimates indicated a slowdown in the fury of new deals between the two countries.

If approved by Congress, the trade pact will lower tariffs on Chinese goods by granting Peking most-favored-nation trading status.

American tariff restrictions have become a focal point in the delicate balance of U.S. relations with China and the Soviet Union. Moscow seeks similar trade benefits, and officials say they expect debate in Congress over whether to grant the Chinese and the Soviets trade concessions, and whether either deserves them in view of their suppression of human rights.

The Chinese seem particularly eager to solidify their new economic ties with Washington as next month's U.S. Soviet summit talks approach.

A veteran U.S. trade analyst said today that business done by americans at the Canton trade fair dropped about 48 percent from last fall's record high. Another well-connected trade promoter revised his estimate of total U.S.-CHINA TRADE THIS YEAR FROM $1.8 BILLION TO $1.5 BILLION.

ANALYSTS GAVE MANY REASONS FOR THE SLOWDOWN, INCLUDING CHINESE PREOCCUPATION WITH DRAFTING A NEW ECONOMIC PLAN AND THE END TO A RUSH OF CHINESE TEXTILE SALES IN THE UNITED STATES. THEY SAID PEKING STILL SHOWS KEEN INTERESTS IN U.S. trade ties, however, giving some preference to American traders here and removing obstacles to the general trade agreement initialed by Commerce Secretary Juanita Kreps here and Chinese Foreign Trade Minister Li Qiang in Peking.

Chinese sales of textiles to American buyers here were estimated to be 50 percent lower than last fall, when China apparently rushed to sell material for cotton shirts and sheets before Washington imposed quotas. Chinese and American negotiators will resume talks next week in Peking to resolve the textile issue. This apparently is one of the last barriers to congressional approval of the trade agreement.

Kreps leaves China Tuesday for Hong Kong and Tokyo before returning to the Unitted States.

"Today we take a major step together in resuming the unimpaired exchange of goods and services-and therefore the exchange of ideas, experience and good will," Kreps said after her negotiating team in Peking telephoned to announce Chinese agreement on a final text.

When Chinese negotiators appeared to be raising many questions about trade agreement details last week, Vice Premier Deng Xiaoping publicly predicted it would be initialed.

"I think the attitude of Vice Premier Deng was very helpful and I think his statement to you carried a great deal of weight with the Chinese government," Kerps told reporters today.

Chinese Vice Foreign Trade Minister Chen Jie indicated to reporters here today, however, continued disagreement over U.S. demands for quota protection of the troubled America textile industry.

"Our exports of textiles comprise only a little more than 1 percent of total U.S. textile imports," Chen said. "That is too small."

John Kamm, Hong Kong representative of the Washington-based National Council for U.S.-China Trade, estimated Chinese textile sales to U.S. purchasers at the trade fair closing Tuesday were only half of the $25 million sold last fall.

"China saw quotas definitely on the way, so . . . she sold everything she could in order to establish a [higher] basis" for the quota negotiations, he said. "By the time this fair rolls around, the most popular [textile] items were fully booked.

Kamm said he has been in contact with 80 to 100 U.S. firms trading here this spring and estimates total American business at about $75 million, down from about $145 million last fall back to about the same level as last spring. Less business is usually done in the spring than in the fall, but the volume of U.S. trade had not dropped so sharply before.

In an interview, Kamm estimated U.S. purchases at about $50 million and sales at about $25 million, compared to last fall's purchases of $62 million and sales of $83 million. Kamm suggested sales dropped because of a Chinese pause to catch up from last fall's heavy sales and to reassess further foreign purchases under the new, scaled-down modernization program.

Chen, the Chinese vice foreign trade minister, appeared to dispute Kamm's estimate of a drop in U.S. purchases. Chen said sales to American businessmen climbed as high as $70 million this fair, but did not elaborate, kamm said his estimate of about a $10 million drop in U.S. purchasers reflected the textile slump, as well as crop failure in Guangdong Province, where Canton is located, that cut into sales of some foodstuffs.

Kamm estimated a record total of 750 american businessmen, and as many as 25,000 traders in all, attended the month-long fair. During the fair's opening week last month, a crush of traders and overseas Chinese on holiday forced Canton hotels to set up beds in hallways. Chinese fair officials said 1,009 American businessmen attended, but U.S. traders said many of those were only sightseeing. The Chinese have not yet released an estimate of total business done at the fair, which Kamm expected would be about $2.1 billion.

C.L. Haslam, Commerce Department general counsel and one of the trade agreement negotiators, said he could not release or discuss any details of the agreement until it is reviewed by both governments and formally signed.

In addition to lowering tariffs, the pact will give both sides new patent protection, procedures to solve disputes and other useful trading rules.

Haslam said the Chinese objected to the great detail in U.S.-requested provisions for patent protection and other items. The final pact, he said, "is the longest and most complicated trade agreement that China hasconcluded with anyone."