SiXiang is a subdivision of Yin and Yang. There are two methods in how SiXiang match four seasons：①orthodox SiXiang theory， which matchs spring with shaoyang， summer with taiyang， autumn with shaoyin， winter with taiyin. This method was widely used in ancient books. ②TCM SiXiang theory， which matchs spring with shaoyang， summer with taiyang， autumn with taiyin， winter with shaoyin. This method was widely used in ancient TCM books. The two method are based on different view of Yin and Yang and so be reasonable in different way . Based on the two SiXiang theory， there are two method on how the SiXiang matches with the five viscera in TCM theory.