Based on the statistical correlation analysis,we find that the monthly mean geopotential height at 500 hPa which can be presented the circulation features over Northern Hemisphere is certain related to maximum earthquakes for Jan.-June and July-Dec. in Yunnan Province. From the stepwise regres-sion forecasting analysis mentioned above,it chooses main circulation factors influencing the earth-quakes,and sets up some regression forecasting equations for the maximum magnitude.