The entomopathogenic fungus, Beauveria bassiana is widely used in integrated pest management (IPM), however its successful application is often limited by the little effort to explore its functions of unknown genes. In this work, egfp-expression cassette was randomly integrated into B. bassiana using Agrobacterium tumefaciensmediated transformation, and the general features of the mutants with unusual characteristics and the localization of the integrated genes were explored. To construct a transformation vector, egfp-expression cassette including gpdA promoter and trpC terminator was cut from pBARKS1-egfp using SacI and HindIII and integrated into pCAMBIA containing hygromycin B resistant hygR gene, designated as pCAMBIA-egfp. Transformed B. bassiana isolates were grown on quarter strength-Sabouraud dextrose agar containing 150 μg hygromycinB ml-1. Expression of egfp was investigated by RT-PCR and a fluorescent microscope (400×). Through the genome walking of the transformants using adaptor primers and gene specific primers, unique bands were detected on the egfp-expressing transformants, which were sequenced to figure out the flanking regions. This work provides a platform of methodology to figure out unknown functional genes of B .bassiana and possibly suggest an improved strategy to use the entomopathogen in IPM.