The aim of this study was to estimate the correlation between performance in running long jumps and the muscular strength of the lower limb's in track and field athletes students. The investigation covered 36 males aged 18-22 years. The results were as follows: 1) There is the significant correlation between performance in running long jumps and performance in a 50 m Run, suggesting that performance in running long jumps is strongly influenced by running speeds. 2) The extension strength of the knee joint or the hip joint may have an effect upon the running speeds. 3) There is a significant correlation between performance in the running long jump and the effective factors (knee extension strength, hip extension strength, and ankle plantan flexion strength). It appears that the lower limb's extension strength excercised a powerful influence on the running long jump. 4) The significant correlation between the running long jump and the effective factors (height and strength of lower limbs) is suggested by the study. Performance in the running long jump would appear to be proportional to the height of the center of gravity; it seems clear that the higher the center of gravity is the greater the advantage in the running long jump.