Abstract: Based on the field investigation, the species diversity of shrub and herb layers under the main plantation types in Xuzhou city were studied by using the Patrick index, Simpson index , ShannonWiener index and Pielou index. The results showed that: (1)In the same plantation, the richness of shrub layer was higher than that of tree layer. The richness of different plantations were big different. (2)Species diversity investigation demonstrates that the species diversity indices of different layer in the same plantation showed an order: herb layer>tree layer. And the indices in the same plantations were different by different methods of species diversity. (3)The Sorenson indices of the seven plantations were 0—0.782 6. The index of Morus alba+ Robinia pseudoacacia and Platycladus orientalis is 0.142 9, the index of P.orientalis and R.pseudoacacia+ Ulmus pumila is 0.133 3,they have less common species, and the largest biodiversities between plantations. The index of P.orientalis+Pistacia chinensis+R.pseudoacacia and P.orientalis+Acer buergerianum+A.mono is 0761 9, the index of R.pseudoacacia+P.orientalis and R.pseudoacacia+U.pumila is 0.782 6, they have the largest common species, and the less biodiversities between plantations.