Based on data of haze days observed by Puyang Meteorological Station of Henan Province from 1971 to 2012,climatic characteristics,causes and prevention countermeasures of haze in Puyang were discussed. The results showed that annual average haze days in Puyang tended to increase slightly over the past 42 years on the whole,and the increasing trend became obvious since the 1990s. Meanwhile,haze days in Puyang showed an obvious seasonal variation,that is,haze mainly appeared in autumn( from September to November) and winter( from December to next February),and it was the most frequent in winter. Haze formation was closely related to meteorological and environment elements. Increase of calm wind in horizontal direction,inversion layer in vertical direction,and increase of suspended particulate matter could lead to aggregation of air pollutants,so that haze days increased. Some countermeasures against haze pollution,such as controlling pollution sources,limiting discharge of vehicle exhaust and industrial gases,and increasing green area,should be adopted to reduce haze harm to air quality and human health.