Abstract: Pilidium concavum tan-brown leaf spot of strawberry was a new disease in China. The disease can cause leaf necrosis and fruit rot. In order to clarify pathogenesis of the pathogen causing tan-brown leaf spot of strawberry, the activity assay and the study on pathogenicity of cell wall degrading enzymes (CWDEs) of Pilidium concavum from strawberry were conducted. The types and activity of CWDEs produced by P. concavum were analyzed by the 3,5-two nitro salicylic acid method (DNS) and ultraviolet spectrophotometer method. The results showed that a series of CWDEs including polygalacturonase (PG), pectin methylgalacturonase (PMG), polygalacturonic acid trans-eliminase (PGTE) and pectin methyl trans-eliminase (PMTE) were detected in artificial culture of P. concavum, but without celluase (Cx). Among the four CWDEs, the activity of PG and PMG were significantly higher than that of PGTE and PMTE. And the optimal culture time of PG and PMG was 6 days, the optimal culture temperature of PMG was 23℃ and of PG was 28℃, shaking alternating culture was good for the production of PG and PMG. In addition, fruit rot and leaf necrosis in strawberry were caused by pectinase (PG and PMG), which indicated that the pectinase from P. concavum played an important role in the process of pathogenicity.