Y　zeolite　was　modified　with　Zr　by　equal　volume　impregnation　method.　The　effects　of　different　amounts　of　Zr　on　the　structure　of　modified　Y　zeolite,　the　physicochemical　properties　of　the　catalyst　and　the　performance　of　hydrocracking　reaction　were　investigated　systematically.　The　modified　Y　zeolite　and　catalyst　were　characterized　by　X-ray　diffraction　(XRD),　NH3　temperature　programmed　desorption　(NH3-TPD),　H2　temperature　programmed　reduction　(H2-TPR)　and　transmission　electron　microscopy　(TEM).　The　results　show　that　Zr　modification　decreased　the　amount　of　acid　sites　of　Y　zeolite,　and　the　trend　became　larger　with　an　increase　of　Zr　content.　Moreover,　Zr　modification　availably　weakened　the　relation　of　metal　species　and　support　in　the　catalyst　with　Y　zeolite,　and　improved　the　dispersion　of　W　species　on　the　catalyst　surface.　The　hydrocracking　reaction　results　suggested　that　VGO　conversion　over　the　catalyst　with　Y　zeolite　modified　with　Zr　decreased　compared　with　that　with　Y　zeolite,　and　middle　distillates　increased　about　20%(mass),　as　well　as　VGO　conversion　gradually　decreased　and　the　middle　distillates　slightly　increased　as　the　Zr　content　increased.　©　All　Right　Reserved.