This paper presented an overview of recent literature on flame retardant polycarbonate/acrylonitrile-butadiene-styrene alloys,the mechanism of thermal decomposition of polycarbonate was also presented.Halogen-free flame retardants including phosphorus,silicone-based compounds and the related flame retarding mechanism were discussed.It was pointed that halogen-free,high efficiency,low toxicity,and environmental friendliness constituted the developing trends for the flame retardants.