Abstract:A random amplified polymorphic DNA (RAPD) analysis was made on the Pardosa pseudoannulata populations collected from eight habitats in Central-south China, Southwest China, and Hainan Island. 10 from 50 primers were selected,and 84 bands of 200-2 500 bp fragments were amplified, among which, 62 bands (73.8%) were polymorphic, suggesting an obvious polymorphism of the populations.As estimated by Shannon index, genetic similarity index and genetic distance, the total genetic diversity index of the spider was 0.5177, with the genetic variation being 64.24% within the P. pseudoannulata populations and 35.76% among the populations. The genetic distance among the eight populations ranged from 0.0753 to 0.3725, with an average of 0.2426, indicating that the eight populations engendered adaptive variations with different habitats. Multiple regression analysis showed that annual mean air temperature and pesticide application were the main factors restricting P. pseudoannulata to be a dominant insect species in rice field.