Abstract: Oriental arborvitae (Platycladus orientalis Franco) plantation communities in Quanshan nature reserve, a typical limestone hill region in Xuzhou city, were surveyed with stratification method. Species biodiversity of plantation communities under three different management intensities were calculated, using Patrick，Simpson, Shannonwiener and Pielou indexes. Results showed that the region with high strength management has the highest plant diversity. The dominant species had naturally converted from oriental arborvitae community with an importance value of 23.59 to black locust (Robinia pseudoacacia Linn.) community, of which importance value was 44.28. In contrast, the lower plant diversity was found in Yunlongshan community with middle management intensity, and the lowest occurred in Xiaotaishan community with weak management intensity. In addition, the plant diversities in different stratification took on an increasing trend from top and ground layers to middle layer for each community.