The purpose of the study was investigate the effect of cool-down and warm-up on Delayed Onset Muscle Soreness(DOMS). 20 healthy male and female student were participated in the study. They were randomly assigned to 4 groups; 1) a control group{n = 5), 2) warm-up group(n = 5) , 3) cool-down group{n = 5), 4) combined group that received warm-up and cool-down. To induce the DOMS at elbow flexor groups of non-dominant arm, they performed eccentric contraction exercises by isokinetic machine(KIN-KOM). The girth of upper arm was measured at the just before, just after exercise, after 24 hr, after 48 hr, after 72 hr, after 96 hr. At the highest point of upper arm, the girth was measured by a tapeline. Muscle soreness level was evaluated at same as above intervals by visual analog scale(VAS). There were significant difference of VAS between groups{P< 0.05). There were no significant difference of upper arm girth between group(P> 0.05). There were no effect of warm-up and cool-down exercise on DOMS and girth.