Pattern of alpha-diversity, the number of species (NSP), along temperature and moisture gradients and the possible explanations are interesting issues in biogeography. However, NSP is highly correlated with the number of individuals (NID). This relationship is explained by the neutral theory: in a given species pool, while all the species have the same ecological equilibrium, NSP is the result of NID. This would change the focus of asked question: from 'why are there more species co-existing together?' into 'why are there more individuals growing together?' National Vegetation Database of Taiwan contains 3564 plots which cover the long gradients of temperature and moisture. Sampling size of each plot is 20 by 20 square meters. All the individuals of woody species with Diameter at Breast Height more than 1 cm in the plot are recorded. In this study, we try to answer the following questions by using this database: 1. What is the pattern of NSP on both gradients? 2. Does NSP do relate to NID? 3. What is the pattern of NID on both gradients? 4. After partitioning the relationship between NID and NSP, is there any remained pattern of NSP on both gradients?