Abstract: Through the experiment of the high protein soybean cultivar Dongnong42 in six seeding dates, researching dynamic samples analysis of chemical quality yield and quality character of the soybeans. We determine the effect of the six periods on the chemical quality yield and quality character of the soybeans, in order to refer the basic of soybean produce theory. Though the experiment of dynamic sampling and surveying nine properties of Dongnong42 soybeans among conformation and yield quality character in six different seeding periods, and use Excel and Spss10.0 to statistically analyzing the materials. Though Dongnong42 in different seeding periods dynamic regular researching show that the effect of different seeding periods on the quality character , chemical quality yield and morphology character are quite much. When the seeding period postpone quality character protein content rise ,oil content decrease in the chemical quality yield, single plant pod quantity, the ration of fresh grain to fresh pod begin to decline, and the ration of main stem low. But effect of circumstances of ray, temperature and precipitation on other characters are striking. Such as plant tall, the average weight of fresh grain and the average weight of fresh pod. The test show that: soybean suitable seeding period in Harbin region HLJ province is from April end to May beginning and middle. If the seeding period is too late, the soybean yield would be terribly effected.