In　the　actual　machining,　installation　and　using　process,　the　problems　of　casing　deformation,　rotor　eccentricity　and　nonuniform　rotor　blade　heights　exist　to　some　extent　in　all　axial-flow　compressors,　resulting　in　circumferential　nonuniform　tip　clearance.　With　the　deepening　of　the　research　on　axial-flow　compressor　flow,　the　nonuniform　clearance　becomes　the　problem　should　be　considered.　The　focus　of　this　investigation　is　on　the　nonuniform　clearance　caused　by　casing　deformation　and　its　effect　on　the　flow　field　characteristics　of　the　rotor　rows.　The　new　parameter　representing　the　nonuniformity　of　tip　clearance　is　recommended,　and　the　modeling　approach　for　the　nonaxisymmetry　compressor　is　introduced.　Three　numerical　models　with　different　tip　clearance　nonuniformities　are　investigated　by　both　steady　and　unsteady　calculations.　The　effects　of　nonuniform　clearance　on　aerodynamic　performance　and　flow　loss　distribution　are　analyzed.　The　unsteady　pressure　fluctuation　and　aerodynamic　force　are　also　discussed.　The　results　indicate　that　the　nonuniform　clearance　can　contribute　to　performance　degradation　and　the　circumferential　asymmetrical　flow　field　in　blade　tip　regions.　Due　to　the　＇wake＇　of　the　upstream　blade　row,　flow　field　asymmetry　of　the　back　rotor　row　is　more　obvious　than　that　of　the　front　rotor　row.　There　is　direct　correspondence　between　the　nonuniform　clearance　layout　and　the　aerodynamic　force　distribution　in　the　circumferential　direction.　The　blade　aerodynamic　force　is　higher　at　small　tip　clearance　regions　and　lower　at　large　tip　clearance　regions,　increasing　the　amplitude　of　the　aerodynamic　force　in　casing　deformation.　©　2016,　Press　of　Chinese　Journal　of　Aeronautics.　All　right　reserved.