To further elucidate the mechanism of Jinggangmycin in controlling rice sheath blight,effects of Jinggangmycin on three cell wall degrading enzymes(CWDEs),i.e. polygalacturnase(PG),cellulase(Cx) and pectin methylgalacturonase(PMG),and soluble mycelial proteins of Rhizoctonia solani,the causal agent of rice sheath blight, were investigated in this research. The results showed that the enzyme activities of all three CWDEs decreased in different degrees at all three tested concentrations of 20, 100,500 μg/mL of Jinggangmycin compared with the blank control(absence of Jinggangmycin,the same in later text). Jinggangmycin at the concentration of 20 μg/mL or 100 μg/mL caused significant reduction at P=0.05 level in enzyme activity of Cx or PG,respectively,when compared with the blank control; however, there was no significant difference at P=0.05 level in enzyme activity of PMG at different concentrations of Jinggangmycin compared with the blank control. By using polyacrylamide gel electrophoresis technique, soluble mycelial proteins of each treatment displayed a pattern of 20 proteinbands with 16 clearer ones when the pathogen was cultured at above mentioned three concentrations of Jinggangmycin. The numbers and the mobility rates of proteinbands were identical, whereas the colour darkness and band width were somewhat different compared with those of the blank control, indicating that the kinds of protein were the same, but the protein contents were different; the band with molecular weight of 90 ku was obviously strengthened at 500 μg/mL, whereas the 6 bands with molecular weights between 16 u and 35 u were obviously weakened at the same concentration,which indicated that Jinggangmycin had certain effect on the soluble mycelial proteins at 500 μg/mL,but no significant effects on the soluble mycelial proteins were observed at concentrations of 20 μg/mL and 100 μg/mL. Taken all together,our study revealed that Jinggangmycin had an impact on CWDEs and soluble mycelial proteins of R.solani weakened the infection of R.solani to rice,and thus it is speculated that this may be one of the mechanisms of rice sheath blight control of Jinggangmycin.