Abstract: Poplar and willow belong to salicaceae plants,both of them were widely used in economic forest,urban afforestation and roadside.Rust was one of the serious diseases that harmed the salicaceae plants,especially in high density planting nursery and pieces of timber forests. The aims of this study was to compare the differences of symptoms,epidemic characteristics and pathological characteristics between the poplar rust and willow rust,and to provide a theoretical and practical guidance for the prevention and treatment of the disease. The field study was carried out in Northeastern Sichuan (including Gaoping district and Xichong county of Nanchong,Qianfeng district and Wusheng country of Guang'an).Epidemiological investigation and microscopic observation technology were adopted in this study.Most of the pathogenic bacteria affected the leaves and seedlings of the poplar and willow,caused leaves to fall off early and the seedlings to wither. But the pathogenic bacteria was Melampsora larici populina (Melampsora larici-populins) for poplar rust; for willow rust,it was Melampsora larici the Hemicriconemoides (Melampsora coleosporioides Diet.).Though there were several same characters between the poplar and willow rust,they were different in the aspects of the symptoms,pathogenic types and occurrence regularity of the disease.It is advised that pertinent prevention and treatment should be chosen according to the different hosts.