The pattern of the seasonal variation of respiration rtae for soil microorganisms was studied on the natural Yang-Cao (Leywus Chinensis) Grassland in Northeast China. The highest rate appears in August.. The "seasonal changes of soil temperature and soil moisture have much effect on the respiration rate of soil bacteria. Both temperature and moisture factors are important to respiration rate and normally correlated with it distinctly by regression analysis. Their coefficients are 0.9999918 and 0.9999365 res...