With U.S.-China trade nearly 100 percent higher in 1979 and major oil drilling and truck deals under discussion, U.S. analysts have concluded that American traders eventually at least should double their current 9 percent share of China's growing import market.

Goods exchanged between the world's richest and the world's most populous nation totalled nearly $2 billion in 1979 compared with $1.15 billion in 1978, China's official news agency reported. But analysts here and in Hong Kong say that American businessmen have yet to feel the full benefit of normalizing relations with Peking. More sales are expected as the Chinese settle into their new economic development plan and as the U.S. Congress approves most-favored-nation status for Chinese trade.

An official study of U.S.-China trade shows that American businessmen sell an average of 18 percent of the imports sought by other nations in the Pacific area. "That means the infrastructure and goods are there for similar U.S. sales to China," one analyst said.

Among major deals still under discussion here with U.S. companies are a truck-producing plant, which General Motors Co. negotiators say would be located in the Wuhan area and cost about $1 billion. Several U.S. oil companies are in the midst of lengthy discussion on joint Chinese-American exploitation of huge Chinese oil reserves both offshore -- where several U.S. companies have been authorized to conduct seismic studies -- and on land. McDonnell Douglas Corp. has been discussing with the Chinese a long-term contract in effect to create a Chinese civilian aircraft industry with the construction and licensing of a plant in Shanghai to manufacture DC9 aircraft.

The Chinese caution, however, that steady progress in trade requires the lifting of restrictions on Chinese goods sold in the United States. "It should be pointed out that while Sino-American trade has been making rapid headway over recent years, the unfavorable balance on the Chinese side has been widening," a leading Chinese trade official, Sun Souchang, said recently.

A Sino-American trade agreement giving most-favored-nation tariff benefits to both sides was signed in July, but must be passed by both houses of Congress. The bill containing the agreement has received initial committee approval. The recent chill in U.S. relations with the Soviet Union is likely to quiet the voices of those congressmen who wished to wait for the consideration of trade benefits for Moscow also.

A final vote on the Chinese trade bill is expected in February. Passage would help the Chinese earn higher profits on their goods sold in the United States -- and thus finance more purchases of U.S. goods -- and open the way for low-cost U.S. Ex-Im Bank loans to Peking. Analysts say the Chinese have shown a distinct preference for these governmental loans in financing their foreign trade. They consider commercial bank loans expensive and complicated.

No matter how much the trade bill improves commerce between China and the United States, such trade is not expected to be a critical factor in the overall U.S. trade balance.

U.S. trade with China remains considerably less than U.S. trade with the Nationalists Chinese-held island of Taiwan, despite the fact that China has nearly 1 billion people and Taiwan only 17 million. "Our trade with China is important because we have a significant political stake in the economic stability and regional strength enjoyed by Peking, not because of any great advantages we expect in our own trade balance," said one American official.

For the moment, the Peking government led by pragmatists such as Vice Premier Deng Xiaoping appears firmly in command and not uncomfortble at all dealing with legions of American capitalist businessmen. Difficulties that have arisen seem to come from Chinese and American unfamiliarity with each other's negotiating practices and Peking's decision a year ago to slow down a flurry of deals in order to assess its complete economic picture. That reassessment, which still continues to a certain extent, left in doubt two large, publicized deals announced a year ago, a series of hotels to be constructed by a subsidiary of Pan American World Airways and a major ore-processing plant to be built by U.S. Steel Corp.

Still analysts appear certain that American companies eventually will profit from China's need for quick improvement in its tourist facilities and in other industries that have become serious bottlenecks in the economy. These include transportation, where the Chinese need more rail lines, roads, pipelines, trucks, locomotives and railcars, and energy, where they need to increase oil, coal and hydroelectric production and also may be considering importation of a nuclear plant.

Through October, the last month for which detailed U.S. Commerce Department figures are available, U.S. exports to China totalled $1.28 billion, and U.S. imports were $458 million. Leading the import list were petroleum at $55.7 million, and textile yarn and fabrics at $52.3 billion. Failure to reach a U.S.-China textile agreement may hold down increases in textile imports, but increased American involvement in oil exploration in China could augment petroleum's importance.

The leading U.S. exports have been grain, including $217 million in unmilled corn and $201 million in wheat through October. Peking has announced a 1979 grain harvest of 315 million metric tons, an increase of 10 million tons since 1978 and apparently the best single national havest in history. The increase does not stay very far ahead of the population, however, particularly because the Chinese have expressed a desire to increase meat production by feeding more grain to animals.

One analyst, predicting continued grain shipments from the United States, said "China's internal transportation network remains jammed up, but the coastal ports can handle grain well, so it makes sense to ship in grain to feed coastal cities." He said the Chinese also may want to increase their depleted reserves in case this year's good harvest, dependent largely on weather, is not repeated.