he effecting of quenching on the performance and structure of WC-Co cemengted carbides has been studied. It has been explored that the quenching of WC-Co cemented carbides had changed not only their binder composition and stress condition but also their microstructural parameters, the effecting extent is related to the to the WC grain size in the alloy. The stability of quenching for the WC - Co alloy in practical operation has been investigated showing the practicality of quenching for WC-Co alloy.