The study is concerned with the division of NSS over Asia into 6 seasons (i.e.spring, early and middle summers, autumn, the first and second halves of winter)based on EOF’s expansion of multiannual data of mean pentad circulations at 500-mb level and surface mean pentad temperature fields as well as on analysis of the annual curves prior to the expansion of time coefficients of the characteristic vectors. In addition, the lengths of each of seasons are determined together with its starting and ending, and a synoptic-statistical analysis is made of the primary features of the circulations within all the seasons.