Abstract: After entering the winter half year,pollution weather of Haikou is easily caused by the weak cold air or downdraft.Using cluster analysis,PSCF and CWT methods,the potential source of heavy pollution weather from October to January during 2013-2015 was analyzed.The result shows that Haikou's air quality is mainly influenced by the northeast air stream from south china and east china during the studied period.The analysis results of PSCF and CWT methods indicate that the most areas of Guangdong,Fujian and Jiangxi province as well as the east of Hunan and Guangxi province are potential areas contributing pollutant for the pollution weather of Haikou.In addition,the main weather system causing air pollution,the exotic impacting from the key area and the accumulation condition of local pollutant should be considered in pollution forecast.