The structural and magnetic properties of Sm2Fe15Si2C and Sm2Fe14CuSi2C were analyzed.The Curie temperature TC and saturation magnetization Ms were measured.The magnetocrystalline anisotropy field HA and anisotropy constant K1 and K2 at temperatures ranging from 1.5K to room temperature were obtained by analyzing the magnetic curve.We can conclude that Cu does not come into the Th2Zn17-type structure,while Cu doping modifies the micro-structure and enhances the coercivity of Sm2Fe14CuSi2C ribbons.The maximum intrinsic coercivity(μ0iHc)around 1.0 and 1.2 T at room temperature for Sm2Fe15Si2C and Sm2Fe14CuSi2C ribbons were achieved, respectively. The microstructural parameter αk and the averaged local effective demagnetization factor Neff were derived from the temperature dependence of coercivity.