Based on the land cover classification system developed by UNFAO, the habitat system of Jiangyin Jiangsu province in years 1991 and 2002 was extracted from the two scenes of Landsat imagery. With these two thematic maps, the sprawl of habitat system and their rank-size distribution patterns were studied. The results showed:(1) the urban area expanded significantly, the expansion was mainly represented as the dramatic growth of small towns, which accounted for 47~ff0 of the total habitat growth, (2) the fractal dimension of the rank-size distribution of the habitat system increased from 1. 253 to 1. 424, which indicated that the habitat system tended to be more uniform, (3) the ratio of bare land area and habitat descended significantly, which might indicate the deceleration of urban sprawl in Jiangyin.