In this paper, (NH4)2S and S 2Cl2 are used as passivating agent for the sulphuration treatment to GaAs0.03Sb0.97. The effect of surface passivation of GaAs0.03Sb0.97 by (NH4)2S and S 2Cl2 treatment is investigated by using photoluminescence (PL), Atomic Force Microscope (AFM). Compared with the pristine sample, the PL intensities of GaAs0.03Sb0.97 that treated by (NH4)2S and S 2Cl2 both are increased significantly. The PL intensity is strongly dependent on passivation time. For the 10s S 2Cl2treated sample, the peak intensity is about 1.4 times larger than 20 min (NH4)2S -treated sample. Meanwhile, AFM images indicate that the roughness of the S 2Cl2 treated sample is smaller than the (NH4)2S treated sample. Thus, S 2Cl2 passivation is an effective method in improving the optical properties of GaAs0.03Sb0.97 material.