The　influence　of　different　spanwise　and　streamwise　blade　thickness　distribution　schemes　on　the　aerodynamic　performance　of　shrouded　centrifugal　compressors　with　arbitrary　spatial　surfaces　was　studied.　The　numerical　results　show　that　the　reasonable　thinning　for　the　equal-thickness　blades　along　spanwise　and　streamwise　direction　can　both　significantly　improve　the　compressor　performance　at　high　flow　operating　conditions　without　obviously　reducing　the　performance　at　low　flow　operating　conditions.　The　performance　improvement　obtained　by　the　spanwise　blade　thinning　and　the　streamwise　blade　thinning　could　be　superimposed.　The　isentropic　efficiency　of　the　compressor　at　the　design　condition　was　improved　by　about　2.08%　by　combining　the　spanwise　and　the　streamwise　blade　thinning.　Compared　to　the　thickness　thinning　of　the　leading　edge　and　the　trailing　edge　of　the　blade,　the　thinning　of　the　blade　tip　thickness　had　a　greater　performance　improvement　capability.　The　research　work　provides　a　useful　guidance　for　the　optimal　design　of　the　three-dimensional　shrouded　centrifugal　compressor　impeller.　©　2020,　Science　Press.　All　right　reserved.