NADPH-diaphorase histochemistry and whole-mount preparation technique were used to investigate the distribution of NOS-positive neurons in gastrointestinal myenteric plexus of Gansu Zokor(Myospalax cansus).The results showed that NOS-positive neurons with different shapes and sizes were widely distributed in the Gansu Zokor's gastrointestinal myenteric plexus.The positive ganglion and positive nerve fibers formed a complex meshwork.There were significant differences in the density of NOS-positive neurons among gastrointestinal tract segments except for Stomach-Ileum and Duodenum-Cecum.The density trend was:colon>small intestine>stomach>caecum.The NOS-positive neurons increased from duodenum to ileum.The results suggest that the distribution of NOS-positive neurons in gastrointestinal myenteric plexus of Gansu Zokor is in similar pattern with that of other animals.