This document calculates and discusses circular groove angle (CGA) affects on journal bearing performance. CFD method has been used for calculate N-S equations and cavitation effect has been considered. The results show that as CGA increases, the maximum pressure is decreased, the capacity and friction moment are also decreased. The maximum pressure position is increased from 1 to 2 when CGA is 180°. This paper will provide a theoretical basis for journal bearing groove optimal design.