Abstract: Light-weight steel multi-storey structures are widely used and developing rapidly all over the world.At the present time,much work on the study of the static behavior has been done,but the analysis of the dynamic properties is rare.Taking a specific engineering as an example,the dynamic properties are analyzed by the finite element software ANSYS,including modal analysis,spectrum analysis,elastoplastic time-history analysis,whose results are compared with those of PKPM.The result shows,the whiplash effect exists,but in comparison,the ground floor is affected more severely in earthquake.