Patterns in species geographic range size are relatively well-known for vertebrates, but still poorly known for plants. Con-trasts of these patterns between groups have rarely been investigated. With a detailed flora and fauna distribution database of Xinjiang, China, we used regression methods, redundancy analysis and random forests to explore the relationship of en-vironment and body size with the geographic range size of plants, mammals and birds in Xinjiang and contrast these pat-terns between plants and animals. We found positive correlations between species range size and body size. The range size of plants was more influenced by water variables, while that of mammals and birds was largely influenced by temperature variables. The productivity variable, i. e., Enhanced Vegetation Index (EVI) was far more correlated with range size than climatic variables for both plants and animals, suggesting that vegetation productivity inferred from remote sensing data may be a good predictor of species range size for both plants and animals.