A　T-section　thin　concrete　encased　steel　(T-TCES)　column　is　proposed　for　the　residual　buildings,　avoiding　the　convex　corners　in　rooms.　The　required　concrete　cover　thickness　for　concrete　encased　steel　members　specified　in　the　existing　codes　is　quite　large,　which　is　the　key　problem　and　to　be　solved　in　the　proposed　column　by　reducing　the　concrete　covers,　facilitating　the　transportation　and　installation.　To　evaluate　the　mechanical　performances　of　the　proposed　columns,　especially　the　local　stability　of　the　internal　T-section　steel　with　the　obviously　reduced　concrete　covers,　tests　of　nine　short　column　specimens　were　conducted　under　axial　monotonic　loading.　Also,　the　finite　element　(FE)　analysis　was　conducted　and　validated.　The　effect　of　the　proportion　of　steel　sectional　area,　concrete　strength,　stirrup　spacing　and　the　concrete　encasement　thickness　outside　the　flange　on　the　failure　modes,　load-displacement　responses,　load-strain　responses　and　characteristic　loads　were　obtained.　According　to　the　test　and　FE　analysis　results,　the　peak　load　can　be　improve　by　increasing　concrete　strength　or　the　proportion　of　steel　sectional　area　or　decreasing　the　stirrup　spacing.　The　T-TCES　columns　with　low-grade　concrete　or　small　stirrup　spacing　or　high　proportion　of　steel　sectional　area　have　a　better　composite　action　between　the　internal　steel　and　concrete.　Increasing　the　thickness　of　the　concrete　encasement　outside　the　flange　can　prevent　the　T-TCES　column　from　cracking.　The　concrete　encasement　and　reinforcement　bars　can　restrain　the　internal　steel　buckling,　and　improve　the　steel　strength　of　the　composite　column　compared　with　the　steel　column.　The　calculation　methods　for　the　peak　and　design　resistances　of　the　T-TCES　column　were　proposed　and　proved　to　show　satisfactory　accuracy.　The　simplified　model　of　the　load-　displacement　responses　and　the　calculation　methods　of　the　axial　stiffness　are　proposed　and　validated　against　the　test　results.