Abstract: Entomogenous fungi is one of the important resources of natural enemies of the insects. The pathogenicity of an isolate of the fungus Metarhizium anisopliae ,originally derived from Holotrichia oblita (Fald.) , against the larvae of them , was studied in the laboratory by immersing larvae into serial concentrations of the fungus. The results showed that the mortality of the larvae caused by infection of Metarhizium anisopliae increased with the concentration of conidial suspension and the time after treatment.The concentration treatment of 2.1×104、1.9×105、2.2×106、2.0×107、1.8×108 conidias / mL caused 20 %,65 %,90 %,100 % and 100 % mortality respectively. A time-dose-mortality model was used to analyze the bioassay data and the model fitted the data well , resulting in parameters for estimating the time and dose effects. The results explained the potential of the isolate of Metarhizium anisopliae for use in microbial control of the larvae of Holotrichia oblita (Fald.).