Using 65Mn steel as friction mates, the wet friction behaviors of 3D- network SiC/Cu composites in 15W Oil 8 mL/（min .cm^2） was investigated under the condition of 1 500 -7 000 r/rain rev and 1.1 -3.9 MPa surface pressure. The 3D - network SiC/Cu composite friction plates exhibited higher friction coefficient than powder metallurgical friction plates did. Two kinds of friction plates showed different failure mechanism. Surface cracks and copper transfer were the failure mechanism of powder metallurgical friction plates, while the main failure mechanism of 3D - network SiC/Cu composite plates was SiC skeleton coated by iron. During friction mating with 65 Mn steel, different extent oxidative wear occurred to two kinds of friction plates, but abrasion wear was the main wearing mechanism of powder metallurgical friction plates , and adhesion due to material transfer was the main wearing mechanism of 3D- network SiC/Cu composite friction plates.