According to the land and socio-economic data of cities at provincial level and above in 2007, using the methods of comparison model and principal component analysis, this paper analyses the characteristics and driving factors of urban land use structure. The results showed: 1) the difference of the proportion of residential land, commercial land and public facilities space, industrial land, road and green space is large, but that of the proportion of warehouse, transportation, municipal utilities is small; 2) with the increasing of city size, the proportion of residential land, commercial land and public facilities space, industrial land and road rise consistenting with the Chinese standard and specification; 3) the cities of residential proportion does not conform to standard mainly beyond the standard cap cities, and the smaller city size, the more serious exceeding the Classification of Land-use and Standards of Urban Construction Land (Standard for short); 4) the cities with low commercial land and public facilities space are with medium sizes above, but it is high in medium and small cities; 5) the proportion of industrial land mainly exceeds the "Standard" in megalopolis, while the cities of industrial land proportion lower than the "Standard" are mainly with medium and small sizes; 6) as city size increases, cities with lower proportion of road and green space than the "Standard" decreases; 7) the proportion of green space is less than "Standard "limit at least 1/3 cities at prefecture level and above in China; 8) the larger the city size, the higher the diversification and the more complete of land use; 9) the cities with higher land use diversity index take on the form of agglomeration; 10) as city size increases, the bigger the equilibrium degree, the lower the dominance degree; 11) the main driving factors of urban land use structure are economic factors, industrial structure, transportion facilities level and urban population, however, the impact order and impact degree on cities withdifferent sizes are different.