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The optical properties of spherical and non-spherical dust aerosols are calculated using the Lorenz-Mie theoryand the combination of T-matrix method and an improved geometric optics method.The resulting opticalproperties are then applied in an interactive system that coupled a general circulation model with an aerosol modelto quantitatively analyze the effect of non-spherical dust aerosol on its direct radiative forcing (DRF).Our resultsshow that the maximum difference in dust instantaneous radiative forcing (IRF) between spherical andnon-spherical particles is 0.27 W m-2 at the top of the atmosphere (TOA) and appears over the Sahara Desert due toenhanced absorption of solar radiation by non-spherical dust.The global annual means of shortwave (longwave)IRFs due to spherical and non-spherical dust aerosols at the TOA for all sky are -0.62 (0.074) W m-2 and -0.61(0.073) W m-2,respectively,and the corresponding values for clear sky are -1.16 (0.092) W m-2 and -1.14 (0.093)W m-2,which indicates that the non-spherical effect of dust has almost no effect on their global annual mean IRFs.However,non-spherical dust displays more evident influences than above on its atmospheric- andland-temperature adjusted radiative forcing (ARF) at the TOA over the Saharan Desert,West Asia,and northernChina,with an approximate maximum increase of 3.0 and decrease of 0.5 W m-2.The global annual means ofshortwave (longwave) ARFs due to spherical and non-spherical dust aerosols are -0.55 (0.052) W m-2 and -0.48(0.049) W m-2 at the TOA for all sky,respectively,and the corresponding values for clear sky are -1.07 (0.066) Wm-2 and -0.95 (0.062) W m-2.All ARFs of dust become much weaker than their corresponding IRFs.The absolutevalues of annual mean ARF for non-spherical dust are approximately 13％ (11.2％) and 6％ (6％) less than those ofspherical dust for the shortwave and longwave for all sky (clear sky),respectively.The results indicate that thenon-spherical effect of dust can reduce their ARFs more obviously than do their IRFs.