Abstract: Taking reed wetland in Panjin as study testbed,the dynamic variation of soil heat flux at different soil depths and the effect of soil temperature on soil heat flux were analyzed.The results show that diurnal and annual variations of soil heat flux present an "S" curve pattern for different soil depths.The amplitude of diurnal variation of soil heat flux obviously decreased along with the soil depth.Daily-averaged soil heat fluxes show high values at 5 cm depth,followed by that at 10 cm depth and 15 cm depth.For soil heat flux in four seasons,the maximum value of daily-averaged soil heat flux is in spring,followed by that in summer and autumn,with the lowest value in winter.The diurnal variations of soil heat flux show the same characteristic under different weather types.The amount of soil heat flux under different weather types in order from largest to smallest is sunny days > cloudy days > rainy days.Soil temperature at 15 cm depth affects the soil heat flux of different depths significantly.The correlation coefficient between soil temperature at 15 cm depth and soil heat flux of different depths become larger along with the depth of the soil layer.