Effects of different treatments of Debaryomyces hansenii on biocontrol efficiency of postharvest diseases were evaluated in this paper.In vitro experiment,D.hansenii at 108CFU(colony-forming unit) / mL provided the best inhibitory zone diameter in the oxford cup.The inhibition zone diameter was up to 20.6 mm.The inhibition rate of spore germination were 5.2% in PDB after 24 hours,and the germtube length were 11.4 μm.In vivo experiment,at the levels of 108CFU / mL,lesion dimameter was 3.6mm,the disease incidence was 7.4%,the midew index was 7.8% and the control efficacy was up to 92.3%.The treatments of antagonistic bacteria could lower the losses of total sugar and Vc.They also could prevent total acid growth caused by mildew.D.hanseniiat at 108CFU significantly preserved the quality of orange and the blue mold was inhibited at 25℃.