The solid culture conditions were optimized using single factor experiment, with the aim to improve the conidium production of a strain of Nomuraea rileyi(Nr19) that was determined to be pathogenic to Spodoptera litura larvae. The results showed that the mixture of soybean and wheat bran is a good fermentation medium for Nr19 and significant increase of yields could be achieved with adequate addition of the mixture bran. Control of stage-specific temperature and relative humidity influenced the culture proc...