Rhizoctonia-diseased specimens were collected from maize plants in different geographic regions in Siehuan Sixteen R．solani AGl-IA isolates and two R．zeae isolates were obtained by tissue isolation and species i-dentification，and were inoculated to determine the pathogenicity，using the leaf sheath inoculation method with 5mmdiscs of pure culture of each isolate in PDA. Lesion length and incubation period were measured. Analysis of datawas performed by using DPS(Data Processing system)computer program. The results showed that the incubation peri-od nf all tested isolates was similar in 36 hr. All isolates were pathogenic to maize. The lesion height and spreading rate were significantly different among the isolates. There was considerable variation in pathogenicity among tested isolateson maize The activities of pectinase(OG、PMG) and eellulase markedly increased with increasing pathogenicity of theisolate It suggested that the activities ofcell wall degrading enzymes(CWDE)were may related to pathogenicity.