Abstract: To investigate the bowing effect of frame structures, practical methods for taking into account bowing effect are studied by using User Programmable Features (UPFs) of ANSYS program. Elastic and non-elastic large displacement analyses are performed for several frame structures taking advantage the numerical analysis of ANSYS. The numerical results show that bowing effect is considerable for shallow frame structures, in which snap-through buckling is likely to happen, thus bowing effect should be accounted for in the analysis of this kind of structures. However, for rectangular frames, bowing effect is negligible in most cases. The approximate expressions of bowing functions can account for bowing effect effectively.