Expression of the long form Leptin receptor mRNA in digestive tract were studied by use of hybridization in situ in 5 SD female rats. The results showed that long form Leptin receptor mRNA was widely expressed in the mucosas and submucosas of stomach and duodenum of rats.The present data suggested that there are long form Leptin receptors in digestive tract of rats,and may provide morphological basis for studying the biological mechanism of Leptin and Leptin receptor.