The　durability　of　post-tensioned　concrete　(PTC)　bridge　structures　has　been　greatly　threatened　by　the　corrosion　of　steel　strands,　especially　in　the　case　of　insufficient　grouting.　In　this　paper,　the　effect　of　grouting　quality　on　flexural　behavior　of　corroded　post-tensioned　concrete　(CPTC)　beams　is　experimentally　investigated　with　two　groups　of　T-beams,　i.e.,　five　fully　grouted　beams　in　Group　A　and　five　partially　grouted　beams　in　Group　B.　Results　indicate　that　when　the　mass　loss　of　steel　strands　in　Group　A　ranges　from　0　%　to　10.47　%,　the　cracking　load　decreases　by　5.8821.57　%,　and　the　ultimate　bearing　capacity　decreases　by　5.45-30.45　%.　While　for　Group　B,　when　the　mass　loss　of　steel　strands　ranges　from　0　%　to　14.26　%,　the　cracking　load　decreases　by　3.75-25.00　%,　and　the　ultimate　bearing　capacity　decreases　by　7.41-44.91　%.　It　is　observed　that　as　the　degree　of　corrosion　increases,　both　cracking　load　and　ultimate　bearing　capacity　of　the　beam　gradually　deteriorate,　with　the　flexural　capacity　of　partially　grouted　beams　deteriorating　faster.　Built　on　this　and　with　the　model　of　bond　reduction　coefficient,　an　analytical　method　is　proposed　to　predict　the　flexural　capacity　of　CPTC　beams　under　different　grouting　conditions.　The　developed　method　provides　good　predictions　compared　with　experimental　results　of　current　study　and　from　literature,　paving　the　way　for　accurate　assessment　of　the　flexural　bearing　capacity　of　PTC　beams　with　different　grouting　qualities　in　corrosive　environments.