The Colorado potato beetle (CPB) Leptinotarsa decemlineata is a major destructive pest of potato crops worldwide. It has dispersed from Kazakhstan into Xinjiang Uygur Autonomous Region (Xinjiang) of China. The dispersal mechanism of an invasive species and its interactions with abiotic and biotic variables of the new environment are critical determinants of spatial pattern and invasion rate. We investigated the relationship between precipitation and the distribution pattern of CPB using ArcGIS spatial analysis tools. Annual and monthly (April to September) precipitation in CPB-colonized and non-colonized regions were analyzed. The climate data were obtained from the website of China Meteorological Data Sharing Service System. Based on the current distribution of CPB in China, we surveyed the occurrence and distribution of CPB in commercial potato fields across 35 cities/counties in northern Xinjiang for a five-year period, from 2008 to 2012. In each city/county, 2-3 villages with potato cultivation were randomly selected for the field survey, and in each village, 2-3 fields were sampled. CPB occurrence data were categorized into five levels: no occurrence (Level 0), light occurrence (Level 1), medium occurrence (Level 2), heavy occurrence (Level 3), and very heavy occurrence (Level 4). From the study results, the annual precipitation was above 150 mm in CPB colonized regions; the regions where CPB affected plants during the preliminary growth stages, such as in Ili Prefecture, had higher rainfall than regions where CPB affected plants in the later, established stage. When correlating CPB colonization with the direction of CPB spread from west to east, we found that annual precipitation was lower where CPB colonization was high. When the CPB spread reached the eastern front of the current distribution in Mori County, the annual precipitation was less than 150 mm, the same as that in the eastern part of Barkol County, Hami Prefecture of Eastern Xinjiang. Further, the precipitation in Southern Xinjiang was less than that in Northern Xinjiang. In the central region of the Tarim Basin, no precipitation was noted for the whole year. Thus, in regions with different CPB damage levels, the precipitation also differed. A linear relationship was noted between the damage level and longitudinal CPB occurrence, where the CPB damage levels decreased with increasing longitude. In addition, less damage was noted in regions with CPB occurrence in later plant stages than in early plant stages. Higher precipitation was noted in Level 2 and 3 regions than in Level 1 and 4 regions. A significant difference was noted between monthly precipitation in the Level 2 and 3 regions and Level 1 and 4 regions from April to September. These months were the main period of CPB damage in Xinjiang. Thus, reduced rainfall leads to a lack of moisture, which plays a role in restricting the spread of CPB. Therefore, our study results show the necessity of strengthening inspection and quarantine measures to prevent CPB from spreading eastward by artificial transmission. In addition, our results highlight the importance of the protection of potatoes and other Solanaceae crops.