The present work has carried out on isolated segments of different parts of the small intestine in rabbits. These segments include duodenum, jejunum and ileum. The solution used for all preparations in this study is Krebs-Henseleit buffer solution and the pH of the solution is adjusted at 7.4. The present study was designed to demonstrate the effect of the following conditions on the motility of different parts of the small intestine, which include the following experiments: Group1: the aim was to study the effect of decreased production of NO (by L-name) on the basal motility of the small intestine. Group2: the aim was to study the effect of NO (by L-name) on motility of small intestine after addition of acetylcholine. Group3: the aim was to study the effect of decreased production of NO (by L-name) on motility of small intestine after the addition of adrenaline. Group4: the aim was to study the effect of increased production of NO (by NO precursor L-arginine) on the basal motility of small intestine.