Conidium germination and approssorium formation rate under eight subatratea, different agar surface with various cAMP and IBMX concentration gradients, different nutrient resource, pH value of conidial suspensison, and cultural filter of antigonistic bacteria were observed. Conidium density of its suspeusion and its pH value did not affect the appressorium formation of Magnaporthe grisea 91-11B1, high density (conidia>10 5/mL) and unsuitable pH value (>10 or <4) would significantly reduce the germination of conidia The hydrophobic substratum surfaces could enhance the appressorium formation, The starvation of nutrition and the surfaces of onion epidermis could stimulate the appressorium morphogenesis, and rich mltrition could inhlbh it, Compared with ion-free pure water,tap water could facilitate the appressorium formation, 2.5mmol/L cAMP and 8.0mmol/L IBMX, the mostly commonly used phosphodiesterase inhibitor, significantly promote apressorium formation. Conidia which collected by vibrating method were more elfective to differentiate into appressorium than those by washing method. Among 13 strains of antagonistic bacteria, three sttains, such as Xb216, Xh240 and Xh220 strongly iuhibited the germination and appressorium formation.