Nowadays, radiation therapy comes to the standard treatment for prostate cancer. There are many critical Organ at Risks (OARs) can be affected during and after the treatment, which can negatively affect patients' later life. In our study, we made comparisons in terms of the optimal dose to target as well as sparing dose to OARs among three techniques 3D-CRT, IMRT and VMAT of prostate cancer. Ten of prostate cancer patients after being treated by IMRT were recruited. The dose influence in PTV was evaluated by Homogeneity index (HI) and Conformation index (CI). Monitor units (MUs) and treatment time (TT) were compared. Three treatment planning met the target coverage (over 95% prescription) and dose distribution. However, IMRT and VMAT showed the optimal dose in mean dose in the target, p<0.05. Besides, distribution dose in OARs of IMRT and VMAT was significantly lower comparing with 3D-CRT planning, p<0.05. MU of IMRT (793.4±37.2) planning illustrated higher than 3D-CRT (305.5±19.80) and VMAT (483.8±21.3). VMAT planning was successful in reducing MU and treatment time. Our study demonstrated that VMAT planning was significantly better in planning quality compared with 3D-CRT and IMRT in the optimal dose to target, OARs and treatment time.