Objectives the aim of the study is to compare the effects of strength training below maximal load for untrained men with pneumatic variable resistance machine (PST) to the effects of strength training with traditional weight and stack units (TST) on the ratio of hamstring to quadriceps femoris maximal isometric muscle strength. Methods 30 healthy men were attributed into two groups, PST group and TST group; they were required to perform 10 weeks progressive resistance strength training with different strength training apparatus separately. Maximal isometric extension and flexion strength at 120 knee angle were measured before and after the strength training. Results after the strength training, peak isometric torque of knee flexors at 120 knee angle (MVC120-F) and ratio of hamstring to quadriceps femoris maximal isometric torque at 120 knee angle (H/Q-120) increased significantly in PST group with the significant decrease of H/Q-120 in TST group. Significant difference of H/Q-120 was found between two groups. Conclusions training within 40-90%1RM load, PST take advantage of increasing the H/Q-120 than TST while TST takes advantage of increasing muscle speed strength than PST; all results indicate a complementary effect between two types of training methods.