Abstract: Through in vestigation and site researches,soil erosion and water runoff in three typical small watersheds in western Guangtong are studied.The results shows that in spite of the more steep slope soil erosion in Gecang watershed is not so serious as in Juntun and Liangtong watersheds.The analysis results shows that the types and quality of the vegetation play a key role on this.The intensive crop plantation,agro-forest sys-tems,and the natural bamboo forest system in Gecang watershed has enabled the farms in this area enjoying an improved environment and higher income.