Abstract: Wetland is a kind of important natural resource with enormous environmental functions and benefits.Cold-humid effect is one of the cumulative environmental effects of wetland.The study on cold-humid effect of wetland will help expose their eco-environmental effects from the angle of water and heat,and provide scientific bases for preservation and rational utilization of wetland.The testing results indicate that cold-humid effect is related to vegetation and seeper depth of wetland.Among the three types of vegetation in the study,i.e.Carex pseudocuraica,C.lasiocarpa and Calamagrostis angustifolia,the first has the deepest seeper and the biggest cold-humid effect.It is then followed by C.lasiocarpa and Calamagrostis angustifolia.The near-ground air temperature and humidity of farmland varied with the distance between farmland and wetland.With increase in the distance,the temperature increased but the humidity decreased,which is mainly the result of the cold-humid effect of wetland.The mean ground temperature of farmlands is 4 ℃ higher than that of Calamagrostis angustifolia wetland and 5 ℃ than that of C.pseudocuraica wetland,which is a significant evidence of the refrigeration effect of wetlands.