Pain is one of the most common medical problems that human encounter with that and permanently search for finding rout that relief this. Previous finding indicated that Cassia Fistula (CF) may be effective in reduction of pain. The present work investigated the effect of CF on acute pain using in Hot plate and Tail flick models. Albino mice (20-30 gram) were used for this study. Hot plate and Tail flick tests were used for evaluation of analgesic effects of the drug. Drug was delivered orally (250 and 500 milligram per killogram) by using an oral gastric tube 30 minute before test. Results indicated that CF has analgesic effect in Tail flick, but not Hot plate test dose dependently (P<0.01). Finding above showed that CF can modulate acute pain. Further research is need to determine the underling mechanisms.