Abstract: In this paper, the amount of soil losses and water runoff, soil moisture content, soil temperature at the plot without litter (A0)and the plot with litter in Pinus yunnanensis forest in middle Yunnan province have been observed. The results showed that the amount of soil lerosion and water runoff in the plot without litter were 13 and 3.3 times higher those in the plot with litter. The mass of the litter was 28.9t· ha-1 and its maximum amount of soil retention was 58.7m3· ha-1. The soil moisture content in the plot with litter is always higher than that in the plot with litter in drought. Therefore the retained forest litter has fine ecological benefits.