Abstract: Knowledge transfer costs are the transaction costs and barriers associated with the process of knowledge transfer. First, the paths of knowledge transfer is analyzed, and it is put forward that cost determinants should be found in the extent, density, speed, and interaction of knowledge transfer from a new perspective. Then the influencing mechanism of these determinants is discussed in detail and the overcoming approaches are provided. They differentiate from the former researches, open the black box of knowledge transfer, integrate their paths, costs and mechanisms. Finally, Suntech power corporation case is studied and the related results are proved.