Abstract: The superconductor Bi₂Sr₂CaCu₂O_x (Bi2212) samples were synthesized by the solid-state reaction method，and the tribological properties were investigated on the friction and wear tester from ambient temperature to liquid nitrogen temperature. The results indicate that the friction coefficient of the Bi2212 against stainless steel is about 0.35 at ambient temperature and abruptly decreases when the temperature is cooled below superconducting transition temperature of the Bi2212，as low as 0. 11. Ag/Bi2212 composites were prepared by sintering Bi2212 with Ag at different mass fractions to improve the tribological properties of Bi2212 at ambient temperature. The structure and morphology were investigated by means of XRD，SEM，and the elemental compositions of the worn surfaces of Ag/Bi2212 composites were determined using energy dispersive X-ray analysis (EDS). The results show that the Ag particles distribute in the Bi2212 matrix，improving the density，flexibility and toughness of Ag/Bi2212 composites，and a soft metallic Ag film forms on the surface of Ag/Bi2212 composite during f riction process and lowers the friction coefficient. The friction coefficient of 10%Ag/Bi2212 against stainless steel shows a lower value (0.2)，and the wear rate of 15%Ag/Bi2212 is minimum 9.5×10^-5 mm³ (N·m)^-1 at ambient temperature. Ag/Bi2212 composites show improved tribological properties.