Abstract: In 2022，four forests with severe incidence of Lecanosticta acicola in Songyang County，Zhejiang Province were selected，from three dimensions：slope orientation，slope position and branch orientation，using the number of lesions as an indicator，analyze the occurrence and development process of diseases. The results indicate that，the impact of slope orientation，slope position，and branch orientation of is，slope direction：south slope＞north slope＞east slope，west slope；slope position：uphill＞mid slope＞downhill＞full slope；branch orientation：east-west＞south＞north.