Habitat quality determines the capacity of regional biodiversity conservation. Assessing the response of regional habitat quality to land use changes can indirectly measure the temporal and spatial changes of regional biodiversity maintenance function and provide a quantitative reference for biodiversity conservation. In this paper, the InVEST-Habitat Quality model was used to simulate the temporal and spatial changes of habitat quality in Lake Nansi Basin from 1980 to 2015. Quantitative assessment the effect of two policy scenarios of returning farmland to forest in hilly areas and returning farmland to forest and wetland in the lake area on the improvement of regional habitat quality. The results showed that the cultivated land, forest land and grassland were transformed into a large number of construction land during 35 years, urban land increased by 40.23% as well as lake area decreased by 35.56% which were mainly converted into reservoir pond. The overall habitat quality of the Lake Nansi Basin is at a low level due to the rapidly development of the industrial and agricultural production as well as the expanding urban land use in the past 35 years, and the current habitat quality is the lowest (0.20). The difference of the intensity of the environmental protection and the intensity of human activities led to the spatial distribution of habitat quality showed the trend of western plain area (0.19) < eastern hilly and mountainou area (0.44) < Lake Nansi area (0.81). In the past 35 years, the area of highly habitat rarity (ie, Habitat Conservation Integrity Index) is mainly in the lake area and the eastern hilly area of the basin. However, the Habitat Rarity Index in some marginal lakes is very low, which is disturbed by human activities. The main reason is that Lake fisheries farming and agricultural activities Scenario analysis showed that returning farmland to forest and wetland in the lake area could increase the average habitat quality by 9.21% while that returning farmland to forest in the hilly area could increase the average habitat quality by 16.75%.