Abstract: The dominant factors of soybean import and contribution rate of each influence factor for the rising import were analyzed by using Constant Market Share Model in the article. At the present stage, the domestic and overseas researcher mainly concentrated on qualitative analysis influence factor on China Soybean Import. Each of factors＂ contribution rate for soybean import growth was analyzed based on research results in domestic and overseas analyzes by quantitative analysis of Constant Market Share Model, so as to take actions according the key factors to reduce the trade deficit of Soybean Import.