A melt-processable fluorine-containing resin composition having an improved thermal stability which comprises a tetrafluoroethylene copolymer, a chlorotrifluoroethylene homo- or co-polymer, or a vinylidene fluoride homo- or co-polymer and at least one thermal stabilizer selected from the group consisting of an amine antioxidant, an organosulfurous compound, an organo tin antioxidant, a tin powder and a zinc powder. The composition can be advantageously processed without causing any trouble even at an optimum sintering temperature of the fluorine-containing resin.