A four span curved HcontinuousH HboxH-girder bridge is used as an engineering example to investigate the effect of radius of curvature on the seismic response of curved bridge. Numerical models with different radii of curvature are created using the finite element analysis program Midas/Civil. The calculation results obtained from response spectrum method show that radius of curvature is an important parameter to curved bridge. When the radius of curvature is large enough, the relationship between seismic response of main girder and radius is approximately linearity, while nonlinear variation is obtained when the radius is not too large. Finally, conclusions are made that seismic design of Hstraight bridgeH unHfoldHed from curved bridge which radius of curvature is specified could Hsatisfy the engineering Hrequirement.