Abstract: Research on spatial heterogeneity of cropland is an important basis for ensuring food security and ecological security. This study analyzed spatio-temporal variations of cropland quantity and cropland quality during 1985 to 2015 based on Remote Sensing（RS) and Geographic Information System（GIS). The results showed that the cropland decreased by 38.87% in the past 30 years. It was characterized with high level of urbanization in the suburbs, where had a special pattern as ‘marginal spreading’ to the loss of cropland, whereas the area of underdeveloped villages featured a pattern of ‘scattered points’ to the loss of cropland. The intensive urban areas and spatial extension areas along the Yangtze River and the Taihu Lake were identified as the hot spot with a huge cropland loss. The reduction of cropland and the expansion of construction land showed a significant consistency in space. It was highly related to the spatial overlay of the rapid-economic-development areas and the concentrated cropland areas. Urban land expansion was the major driver force to cropland loss. Due to the impact of economic development level and agricultural development policy, the adjustment between cropland and other land use types varied in different stages. The roll-in and roll-out of cropland did not match both in surface area and quality. Generally, the change pattern of cropland shifted from a slow-scattered loss to a rapid-agglomeration loss. The distribution pattern of cropland with steep variation（in both quantity and quality) had shifted from dispersion to centralization, which was also showed in the cropland with slowly variation. It drives the dominant area of cropland shift from the plains surrounding Taihu Lake to the hilly area in the southwest.