Abstract: With the increase of population and the development of economy, the land use change is more notable, and causes the change of eco-environmental background of land resources. Studying the effect of land use change on eco-environment can improve the conditions of agricultural production, and make the regional economy and ecoenvironment develop in a good way. Taking Qian Gorlos County as an example,the paper analyses the pattern of land use change, it shows that there was an obvious decrease in the area of grassland and forestland, while wasteland and paddy field increased in 1986 and 1996. Then the paper studies the effect of land use change on the eco-environment, the effect shows mainly at three aspects: ⑴ Land deterioration aggravated. Not only the area of land deterioration was enlarged, but also the degree of land deterioration was aggravated. ⑵ Water pollution was serious. With the farmland area enlarged and amount of irrigation water increased, the agricultural drainage resulted in water quality worsened. ⑶ Bio-diversity decreased. With the land use pattern changed, the landscape fraction increased while the dimension of patches decreased.