The diversities of the composition and spatial distribution of soil types and land use types in Xi’ an City and their correlation in 1995, 2005 and 2010 were analyzed by using the modified Shannon entropy formulate respectively. The results showed that with the increase of altitude, the soil forming factors tended to be complex and the diversity of soil composition decreased gradually. Soil distribution was relatively homogeneous with the composition diversity index of 0.78. Land use chaos were increased inconspicuously with a bit increment of the diversity index of soil composition by 0.011 and 0.008 during 1995—2005 and 2009—2010, respectively. Only 6 of 51 soil types had the spatial diversity higher than 0.65, rocky brown soil had the largest area and highest spatial diversity index (0.793), but loessal soil had the lowest spatial diversity index (0.023). The diversity indexes of all the land use types were higher than 0.7 except the unused land, in which farmland had the highest spatial diversity index (0.927). From 1995 to 2010, the area of farmland decreased by 185.119 km² but construction land increased by 193.677 km², and they changed more rapidly from 2005 to 2010, meanwhile, their diversity indexes slightly decreased. The oil soil and loessal soil had largest areas in farmland and construction land, and all correlation coefficients between the two soils were higher than 0.8. The above results prove that Shannon entropy is an effective in estimating soil diversity, and the expansion of Xi’an City from 1995 to 2010 only occupied little cultivated soil, indicating the important soil types are secure at present, but more attentions should be paid to gradually enlarged occupation of oil soil.