To investigate the +Gz protection of the on board oxygen generating system (OBOGS) and anti-G equipment.Physical and physiological tests of the OBOGS and anti-G equipment were accomplished using human centrifuge. +Gz tolerance of ten male subjects with or without the anti-G suit, pressure breathing for G (PBG) and OBOGS were determined.The performance of the OBOGS and anti-G equipment fulfilled the requirements. The +Gz protections of the anti-G suit, PBG, and anti-G system were 2.08 G, 1.92 G, and 3.92 G, respectively.The +Gz protection of the OBOGS and anti-G equipment satisfy the performance requirements of high performance aircraft.