| Two kinds of cultivation methods were employed to produce conidia powder of Beauveria bassiana (Bal s.) Vuill, which was used for manufacture of the fungal suspension emulsion at the concentration of 5.48×1010conidia/g.19 kinds of chemical auxiliaries were used to co-cocultivated with B. bassiana spores, in which the chemical auxiliaries grease armour, in which SC-1050,600#,7227-A, S, D-425, P, N, H, and 601 showed limited impact on spore germination, while the other chemical auxiliaries indicated influence on spore germination with the different diluted concentrations, the chemical auxiliaries Chitooligosaccharide significantly influence the spore germination of B. bassiana. According to the combination test result of all chemical auxiliaries, including suspension rate, emulsion time and viscosity, two groups of suspension emulsion were selected, they are suspension emulsion 1#:S 3%; C0.5%; H0.5%; D 2‰and suspension emulsion 2#:600#2.5%; P0.5%; H 0.5%; D 2%o, respectively. B. bassiana 20% volume of the fungal spores powder was determined finally, used for two suspension emulsions' manufacture, via the scattered speed, particles sedimentation, atomization and adsorption effect, respectively. It showed no significant difference between the fungal power and two kinds of suspension emulsions on conidial germination rate, while the uspension emulsion 2# showed an positive effect on fungal spore germination. The laboratory bioactivity test showed that the B. bassiana suspension emulsion 2# improved toxicity against the larvae of Ostrinia furnacalis compared to that of fungal power. the results were consistent with the spore germination rate results.Field control trial of different fungal formulations against O. furnacalis indicated that B. bassiana granules, B. bassiana suspension emulsion 1#, B. bassiana suspension emulsion 2# and chemical pesticide Kebaiwei, showed obvious effect, compared that of blank control, the filed used no pesticide. It mainly displayed shorter tunnel length, increasing bombysbatryticatus or cadaver, and the enhancement of corn yield. Control efficiency was granules> suspension emulsion 2#> suspension emulsion 1#> Kebaiwei. The control efficiency of both two B. bassiana suspension emulsions in this research was higher than that of chemical pesticide Kebaiwei, were potential for further development. The population density of B. bassiana was investigated in corn fields, that used different fungal formulations and blank control, at different internal after usage of the pesticide. Dodine-oat medium was used as the most efficient selective medium for monitoring. The fungal spores were collected by the medium from leaves, air and soil, respectively, to undertake the dynamic tracking of the fungal population. It was detected that the fungal population density in different formulations reated fields used were higher than that in control field obviously. The most concentrated fungal population appeared in one hour after treatment, the contents of B. bassiana followed the sequence leaves>air>soil. Then, it decreased quickly of the fungal populations over time on leaves and in soil, especially in leaves, while it was relatively stable in air. B. bassiana suspension emulsion 2# showed a higher adsorption ability than the other formulations, it was potential for enhancing the efficacy.
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