Abstract: Using the half hourly datas of turbulence flux which observed by the eddy covariance (EC) from July, 2007 to June, 2008 at Shouxian climate observatory in Huaihe River Basin. Analyze the Seasonal and Diurnal Variations of CO2 flux and heat flux in the surface layer. The results show that CO2 flux and heat flux have characteristics of significant Seasonal and Diurnal Variations. The variation of diurnal amplitude is variations with season , showing that the flux amplitude in summer and spring is larger and smaller in winter and autumn ；The average CO2 flux in summer and spring is larger and only about -0.051 mg﹒m-2﹒h-1 ～-0.047 mg﹒m-2﹒h-1 （the paddy and wheat growing period ）in the period when the cropland without crops or covered with snow .It is obviously that CO2 is always absorbed by the crops as the average CO2 fluxes during the experimental period is about -0.59mg﹒m-2﹒h-1。Net radiation and latent flux are maxima in May and minima in January.