The objectives of this study were to optimize the best dose of mifepristone injections in combination with PmPG synchronization protocols and the use of fixed-time artificial insemination (FTAI) to enhance the reproductive efficiency and the use of superior genetics of Chinese crossbred buffalo heifers. A total of 155 heifers were synchronized with PmPGMH in different doses (0.3mg/kg, 0.4mg/kg and 0.5mg/kg) of mifepristone. PmPGMH in mifepristone dose of 0.3mg/kg showed the highest significant (P < 0.05) estrus rate (84.2%), ovulation rate (89.5%) and conception rate (52.6%) among other methods. Furthermore, 41 crossbred buffaloes were subjected to single FTAI using PmPGMH at hours 16，20，24, 28 and 32 of mifepristone dose (0.3mg/kg) treatment to select the best AI time, the results showed that TAI at hours 24 was the best insemination time.