The purpose of this study was to identify whether or not in one-leg vertical jump of each limb asymmetry between both sides is present and to identify how the discrepancies between both limbs affect two-leg jumping performance, that is bilateral deficit. We had 13 healthy subjects perform one-leg jump for both sides and two-leg countermovement jump. The result of biomechanical analysis showed significantly difference of 4-7% in net impulses and work output between dominant and non-dominant one-leg jump and bilateral deficit of 24% when sum of those of each one-leg jump was compared with two-leg jump. But asymmetry in lower extremity was not significantly correlated with bilateral deficit. Two-leg jump could be characterized by relatively short propulsion time, long propulsion distance and high joint angular velocity compared with one-leg jump. These factors seemed to contribute to decreased performance in two-leg jump. Furthermore bilateral deficit was attributed to lower activities of extensor muscles found in two-leg jump.