Abstract: A composition of thermally conductive flame-retarded plastic comprises of: (A) 5 wt % to 45 wt % of polyolefines; (B) 3 wt % to 25 wt % of thermoplastic elastomer; (C) 35 wt % to 85 wt % of thermal conductive fillers; (D) 5 wt % to 55 wt % of flame retardant additive free of halogen, phosphorus and nitrogen; and (E) 0.5 wt % to 6 wt % of coupling agents. The composition exhibits high surface impedance and meets at least the UL94 V1 rating. The composition has a thermal conductivity greater than 1.0 Watts/m-K, a heat deflection temperature greater than 105° C. Besides, the composition is easy to mold and can be made by the method of injection, extrusion or thermoforming.