The dose response carve of morphine and atropine against 5-HT and acetylcholine have been worked out in the isolated rat uterus. The direct nervous effect of 5-HT have been quantitatively estimated to constitute about 15% of its total effect. The mechanism of action of various nervous blocking drugs has also been suggested. Percent blockade exhibited by different doses of morphine (M) to the agonistic activities of 1 ug/5 ml 5-HT in the isolated rat uterus and percent contraction shown by 1.0 ug/ 5 ml acetylcholine in the presence of different doses of morphine the isolated rat uterus have been tabulated in detail.