Soy food products, from the global viewpoint, are one of very important foodstuff to contribute to resolve difficult problems such as natural environment including food resources, social environment dealing with health oriented people and economic environment to pursue the reduction of medical costs. Because soy food products play an essential role in solving three global bottom lines, it is very effective and valuable to elucidate causal relationship of Knowledge, attitude, purchasing and consuming. Clarification of causal relationship becomes clue to increase soy consumption. In the previous studies, there are several research papers which partially verify some results of causal relationship. These results of verification can be refered to set the hypothetical model. In the empirical analysis, research techniques adopted is structural equation model. The results have been verified. In brief, there is a chain of causal relationship of knowledge, attitude and purchasing of soy food products. Moreover, further research should be carried out to resolve a chain of causal relationship, since the previous studies supporting these results have been quite a few. It is no doubt that continual research will contribute to strengthen the relation between health promoting behavior and consumer behavior.