The L.arginine-Nitric oxide pathway has shown a role in pain felling which is a mediator with modulation effect in dorsal root of ganglionic neurons of spinal cord. The presented study goal was to clarify the influence of sex on the effects of L.arginine mediated nitric oxide on pain arbitration in both sexes of mice. The response time of hot plat test and latency period of tail flick were recorded the pain perception. The results of both groups of control and treated with L.arginine showed decrease of time response of hot plat in male than female and the same result in tail flick latency period of control group. Where as amplify of hot plat response time of male than female in L.NAME (nitric oxide synthase inhibitor) treated group. Morphine treated group were increase in all groups as compared with control. These findings might be attributed to that pain felling is intercede through diverse mediators in different sexes of mice male and female, this may possible involves sex hormone. In addition, from the result of L.NAME on pain sensation, it may be recommended that L.arginine-nitric oxide pathway is extra vital in male in comparison with female in pain sensation.