This　paper　reviewed　and　enunciated　the　flame　retardant　mechanisms　of　polycarbonate　(PC)　Iacrylonitrile-butadiene-styrene　copolymer　(ABS)　containing　aromatic　phosphates　and　of　PC　containing　silicone　or　sulfur　compounds　as　well　as　the　decomposition　mechanism　of　PC.　Several　typical　reactions　were　involved,　such　as　rearrangement　of　carbonate　group,　reaction　between　hydroxy　compounds　and　PC,　Fries　rearrangement,　rupture　of　isopropylidene　linkage　and　thermal　oxidation　of　PC,　etc.　One　of　the　emphases　in　the　further　research　is　to　acquire　more　relevant　experimental　evidences　to　substantiate　and　further　consummate　the　proposed　mechanisms.