Abstract: This article introduced an overview of the growth of synthetic diamond single crystals, by the highpressure and hightemperature (HPHT) method and the chemical vapor deposition (CVD) method. The advantages and disadvantages of two main CVD technologies, which are hot flame CVD and microwave CVD, were compared. The research development of doping diamond to P and N types,the doping effects of N, Li, Na, P, S, and the impact of BS codoping were also presented.