Abstract: The vertical and horizontal distributions of Pseudorobitis gibbus adults on Lagerstroemia indica were analyzed by using the aggregation indices and geostatistics. The results from aggregation index methods indicated that its vertical distribution was an aggregated distribution, and the aggregation average (λ) was above two, showing that the aggregation resulted from its bionomics and behaviors, not from the environmental factors. The results of geostatistic analysis showed that the best fitting models for the five different sampling data in June 4, June 16, June 29, July 25 and August 22 were Gaussian, Gaussian, Linear, Gaussian and Linear models, respectively, but random models in July 12 and August 7. It was concluded that the horizontal distribution of the pest was aggregated on the whole, and there existed a spatial correlation ranging from 1.68 to 9.79 m on the different dates.