Abstract: In this paper， a poly（ISB-co-CHDM carbonate）/bisphenol-A polycarbonate alloy was prepared at a mass ratio of 50/50， and the effect of refractive index differences of raw materials on the appearance of the alloy was investigated. The glass-transition temperature of the alloy was determined by DSC， and the compatibility between two phases was explored. The results indicated that the two phases of the alloy were partially compatible. The effect of antioxidant （AO300） content on the glass-transition temperature and transmittance of the alloy were studied. The results indicated that when 9 phr of AO300 was added， the transmittance of the alloy reached 82 %. This suggests that the alloy basically became a fully compatible system. The effects of flexibilizers （M577 and M732） on the mechanicals properties， heat deformation temperature， and melting flow rate of the alloy were investigated. The results indicated that M577 generated a better toughening effect than M732. The effect of different types of compatibilizers on the material properties of the alloy was compared. The results indicated that the GMA-type compatibilizers enhanced the compatibility of the alloy and generated a significant influence on its fluidity. Based on the use of compatibilizers and flexibilizers， the alloy can meet the requirement of practical use.

Key words: bisphenol-A polycarbonate, poly（ISB-co-CHDM carbonate）, flexibilizer, compatibilizer, polymeric alloy, refractive index