Effects influencing factors,such as Trichogramma species,Trichogramma quality,release skill in the field,field conditions,natural enemies,chemical pesticides,population of Ostrinia furnacalis,were summarized in the paper.Effective measures of improving control efficacy of Trichogramma den-drolimi Matsumura against Ostrinia Furnacalis Guenée were summed up,i.e.,try to improve quality of Trichogramma species and breeding quality,try to reduce effect of field conditions,natural enemies,chemical pesticides.