Effect of covering plastic film technique in furrow on yield and population physiology in soybean was studied,with high photosynthetic efficiency soybean cultivar Heilong 40 as material.The results indicated this cultivation technique could increase soybean seed yield greatly,and the range of yield increment was 21%~25.4%。The targets of photosynthetic physiology were more improved than that of CK,also including biological and economic yield.These results showed the population physiology basis of covering plastic film in soybean furrow.