In steel structures, the mechanical characteristics and the hysteretic behavior during dynamic behavior is different to those during static deformation. This is due to the coupled effect of strain rate hardening and temperature rise. To predict hysteretic behavior of steel structures under dynamic/cyclic loading such as earthquake, it is therefore necessary to develop a rate-dependent hysteresis model which can accurately describe the static-dynamic mechanical characteristics considered the coupled effect of strain rate hardening and temperature rise as well as the hysteretic behavior. In this paper, to develop a rate-dependent hysteresis model of SM490(structural steel according to Korean standard), the monotonic and cyclic loading tests were performed for strain rate. Based on the test results, the rate-dependent hysteresis model of SM490 was formulated and with the material parameters used, the model was derived. The validity and the accuracy of the developed model were verified by comparing between the analyses and the experiments. The comparison results show that the rate-dependent hysteresis model of SM490 developed by the authors can accurately predict the static-dynamic hysteretic behavior of steel structures under cyclic loading.