In the principle of the information entropy, the dynamical changes and temporal-spatial variations on the land use structures for the city group are analyzed by means of their land use data and the corresponding economical resources. These results shows: in principle, the proportions of farmland, garden, water and unused land are decreasing, whereas the areas of settlement sites and mining land, traffic land rapidly enhance. The information entropy of land use structures at first increases and then decreases, until eventually and continuously increases during the research period from the year of 1996 to 2008. Based on the analysis of the land use structures and internal structure of agricultural land, the proportions of woodland, orchard garden, mulberry field, traffic land are found to be the important factors that affect the information entropy of the land use structures. The temporal and spatial diversities are evidently observed in the information entropy of counties.