In noninertial coordinate system,the Lshaped columns element stiffness matrix was derived from the study of loadbearing capacity of the Lshaped columns considering shear deformation effects.Using the matrix,a finite element program of Lshaped column frame structure internal forces analysis was compiled.A 3layer frame structure was calculated and a comparative study is made of the ANSYS calculation results and the calculation results of equivalent rectangular columns.Conclusions are drawn that shear deformation of the Lshaped column is greatly different from that of equivalent rectangular column;the torque of Lshaped column is influenced greatly whether considering the effects of reverse or not.