In order to accurately calculate the deflection of concrete composite girder with corrugated steel webs，the initial parameter equations of deflection curve of the girder，which take into consideration the influence of shear deformation，were deduced． In the investigation，first，the distribution characteristics of the shear stress in girder sections were analyzed，and a simplified formula for calculating the shear stress in webs was obtained． Then，the initial parameter equations of deflection curve of the girder were deduced，and a deflection calculation method was put forward． Moreover，the deflection of concrete composite girder with corrugated steel webs under three typical loads，namely the midspan-concentrated load，the symmetrical load and the uniformly-distributed load，was ana-lyzed by using the proposed method，and the results were compared with those obtained by experiments and finite element analysis，finding that the proposed theoretical method is accurate and applicable． Finally，by using the proposed method and the finite element method，the influences of depth-to-span ratio and aspect ratio on the shear deformation of the composite girder were explored，and a limit value of depth-to-span ratio was suggested for deter-mining whether the influence of shear deformation should be considered during the deflection calculation．