Abstract: Objective To observe the cellular morphological and histological changes of the reconstructed tongue defect by rectus abdominis musculoperitoneal flap of dogs with or without nerve.Methods 12 Beagle dogs were randomly divided into two groups. Group A made rectus abdominis musculoperitoneal flap with the intercostal nerve while group B without the intercostal nerve. Nerve anastomosis was performed in Group A while not in Group B in the repairment. 12 weeks later, the length, width, surface area and cellular morphology and histological changes of the two transfer flaps were observed.Results The length, width, surface area of transplanted rectus abdominis musculoperitoneal flaps in group A were greater than those in Group B, and the differences were statistically significant at 12th week （P<0.01）. The microscope study found that the transplanted rectus abdominis musculoperitoneal flaps of group A had part of muscle fiber atrophy with some connective and adipose tissue, loose muscle fiber arrangement, while the transplanted rectus abdominis musculoperitoneal flaps of Group B had muscle cells atrophy with some adipocyte. The structure of muscle cells in Group A was basically normal, but it was disorder in Group B. The type Ⅱ muscle fibers of Group B was atrophy and substituted by a lot of connective tissue. Conclusion After tongue defect reconstructed by rectus abdominis musculoperitoneal flap with nerve, the changes of muscle fibers could be similar to tongue muscles, providing a basis for the dynamic recovery of the tongue.