Abstract: One of the features of the light weight steel frames is low ductility. In this paper, a series of test results on non-compact and slender H-shaped members are summarized. It is suggested that the axial compression ratio and the width-to-thickness ratio of flange and web of members shall satisfy the requirements of the seismic loading capacity and deformability. The failure mode and energy dissipation mechanism of the frames are studied experimentally and numerically, and key factors in terms of the ratio of resistance and stiffness are found. A seismic design procedure according to the low-ductility behavior is proposed.