Despite a widening trade deficit, China's sales to America have increased faster than its purchases from America, According to U.S. trade statistics released here last week.

Figures for the first three months of this year show that Chinese exports to the United States grew gy 84 percent over their level for the same period of 1980, while China's imports rose by 53 percent.

Despite the relative gain in Chinese exports, Peking's overall sales to the United States are still so low compared to its imports that its latest success does nothing to offset the huge imblance in Sino-American trade: China's deficit in the first three months of this year reached $805 million compared with $570 million in the same period of 1980.

Accounting for the largest increases in Chinese exports were textiles, clothing, peanuts and such nonferrous metals as tin, tungsten and titanium, according to the report prepared by U.S. Commerce Department officials.

Economic analysts said the statistics reveal an unexpected and dramatic reversal in the pattern of bilateral trade. Since the two nations normalized relations in 1979, Peking's imports from America consistently have risen at a much faster rate than exports.

Partly explaining the sudden shift is Peking's new austerity program, which cuts back on imports of costly equipment from the West Analysts also cite the special needs of the American economy caused by such events as a poor peanut harvest in 1980.

Chinese officials who bitterly complain about the trade imbalance may be heartened by the latest statistics but chastened by the enormous disparity that continues to widen despite improvements in Peking's relative standing.

Trade proponents on both sides of the ocean, however, could be buoyed by the over all increase of 60 percent in bilateral sales in the first three months of this year compared with 1980. Two-way trade reached a new high of $1.56 billion from Januray to April.

U.S. exports to China hit $1.18 billion compared with $774.8 million in the first three months of 1980. Chinese exports to America increased from $205.7 million in 1980 to $378.7 million this year.

Among the most successful Chinese exports were textiles and clothing despite a treaty signed last year that purportedly limited Chinese textile sales to U.S. firms. Sales increased from $68 million last year to $156 million this year.

Other Chinese exports that rose dramatically in the first quarter of this year were oil seeds and peanuts, which accounted for $34.8 million compared with no sales last year. Sales of nonferrous ores jumped from $4.3 million in the first quarter of 1980 to $15.3 million this year.

Of U.S. exports to China, agricultural products continued to occupy more than 60 percent of sales. Wheat exports showed the most dramatic rise, increasing from $55 million in the first quarter of 1980 to $352 million this year. Raw cotton and fertilizers also registered hefty increases.

Reflecting China's new austerity drive, however, U.S. sales of oil-drilling machinery and parts dropped, as did exports of chemical elements and compounds.