Based on a new multi-shape ice cloud radiative parameterization scheme and the Beijing Climate Center radiative transfer mode (BCC_RAD), the effects of the Henyey-Greenstein (HG) approximation on the shortwave ice-cloud radiation are analyzed in details, in which the HG approximation is widely used in radiative calculations. To the optical properties of the single ice crystal, the HG approximation causes large errors on 3 rd and 4 th coefficients of the Legendre expansion of the phase function, and the maximum values of the errors are -0.28 and -0.33, respectively, while the maximum values of the relative errors are -55.7% and -73.8%, respectively. The errors of 4 th coefficients are higher than those of 3 rd coefficients, and the errors in near-infrared waves are higher than those in visible waves. To the bulk optical properties of the ice clouds, the HG approximation causes large errors on 3 rd and 4 th coefficients, and the maximum values of the errors are -0.18 and -0.22, respectively, while the maximum values of the relative errors are -27.9% and -37.1%, respectively. The errors of 4 th coefficients are higher and so as in visible waves, which are same to the single ice crystal. The HG approximation also causes large errors on the radiative calculations. The maximum value of the errors on the shortwave downward fluxes is -2.78 W·m -2, and on the shortwave upward fluxes is -1.06 W·m -2, while on the shortwave heating rates is 0.27 K·d -1. The HG approximation underestimates the shortwave downward fluxes and overestimates the shortwave heating rates. Therefore, phase function accurately describing on ice clouds radiation transfer is necessary.