Front-month January soybeans reached $13.46-3/4 a bushel, the highest spot soy price since Sept. 19, before paring gains and settling at $13.43-3/4.
USDA said private exporters reported sales of 290,000 tonnes of US soybeans to China, including 230,000 tonnes for delivery in 2013/14 and the rest in 2014/15.
USDA reported export inspections of US soybeans in the latest week at 60.430 million bushels, exceeding a range of trade expectations for 48 million to 55 million bushels.
Cash bids for soybeans shipped by barge to the US Gulf Coast firmed early on Monday, supported by strong overseas demand.
Top global soy buyer China imported 6.03 million tonnes of soybeans in November, up 43.9 percent from 4.19 million tonnes in October, Chinese customs data showed.
Chinese imports of vegetable oils in November were 770,000 tonnes, up 42.6 percent from the previous month.
Analysts expect the USDA's monthly supply/demand report due on Tuesday to show 2013/14 US soybean ending stocks at 153 million bushels, down from the USDA's November estimate of 170 million.
Gains were limited by expectations for a record-large soy crop in Brazil. A cold front will bring rain to all of Brazil's soy regions this week, Sao Paulo-based weather forecaster Somar said, continuing a season of strong rainfall.
CBOT soymeal followed soybeans higher and gained against soyoil on meal/oil spreading.
Malaysian palm oil futures fell as investors booked profits ahead of stocks and output data due Tuesday from Malaysian Palm Oil Board, but monsoon floods stoked supply concerns of the edible oil and propped up prices.
CBOT reported no deliveries on the December soymeal contract, while December soyoil deliveries totaled 124 lots. Both contracts expire on Friday.