Panxi area is the main produetion base of mulberry trees in Sichuan Province. With the developments of silkworm industry and planting mulberry trees, diseases of the mulberry trees become more and more serious, which influences greathy the advance of the industry in the area. To get a better understanding of the occurrences of these diseases, investigations into their kinds, distributions and symptoms have been carried out since 2001. These results have indicated there are 17 kinds of diseases in the area, among which 8 kinds are the main harmful ones. To prevent and control these diseases, some corresponding countermeasures have been put forward by the authors.