In the context of ECMWF May-September 1980～1986 series and EOF technique, investigation is performed of the temporal variation in the behaviors of Indian and east Asian monsoon circulations,indicating that the first t hree principal components of the involved elements show not iceable discrepancy in explaining total variance of pert urbation with great difference between the two monsoon areas;signs of time coefficients related to the first two principal components for the seasonal trend are reversed at least one pentad earlier in the Indian than in the other region;dist urbance of meridional wind is less clear than that of the other elements as regards seasonal trend;the temporal coefficients of eigenvect ors for nonseasonal trend differ greatly in phase space traject ories between the regions.