This study aimed to determine whether velocity of downward(eccentric:ECC) phase affect jump height, mean and peak velocity,power, force, and rate of force development (RFD) of upward(concentric:CON) phase during jump squat (JSQ) with moderateload. Fifteen university rugby players were performed JSQconducted with ECC velocity of 2 seconds (ECC2s) and theirmaximum velocity (ECCMax) at 30% and 50% load of squatone repetition maximum (SQ1RM). JSQ with ECCMax showedsignificantly higher values of jumping height, mean and peakvelocity, power, force, and RFD, in comparison with JSQ withECC2s. These results suggest that during JSQ with a moderateload, performance of CON phase was revealed to be enhancedwith faster velocity of ECC phase.