Combined bending and axial compression for L-shaped reinforced concrete short columns is a common problem. But the present ACI Building Code (ACI 318-77), handbooks and texbooks pay no attention to this problem. A numerical analysis and computer program developed by Hsu fora reinforced concrete member subject to biaxial bending and axial load has been used Using this computer program, the interaction diagrams and failure surface were developed for L-shaped members under combined bending and axial compression. A comparison between theoretical and experimental results was included to examine the validity of failure surface.