The mix proportion design method of recycled concrete by close packing method of mechanically interlocked skeleton was studied, aiming at the various qualities of materials, surface properties and compact degree of recycled concrete aggregates (RCA) from different kinds. The proportion tests of four different kinds of RCA as the aggregate were carried out with the amount determination of RCA and cementing materials by close packing degree of RCA, and mortaraggregate ratio respectively. It was found that the amount of cementing materials determinated by mortaraggregate ratio was more appropriate than that by richmortar coefficient. In the testing condition, the preferable mortaraggregate ratio of C40 recycled concrete was near 0.49. And the slumps of the concretes and the 28 d compressive strengths reached at 155 mm and 52 MPa, respectively.