Objective      To explore the effect of radiotherapy on platysma myocutaneous flap (PMF) after esophageal reconstruction in dogs.        Methods      Eleven healthy adult dogs with PMF imbedding esophagus were randomly divided into three groups: prophylactic radiation dose (4 000 cGy)

radical cure radiation dose (6 400 cGy) and control group. Foodintake

early radiotherapeutic reaction of esophagus and PMF were surveyed

and stoma condition was observed with barium swallow esophagogram before and after radiation. After killing these dogs

we surveyed the compliance of PMF and esophagus

and the vitodynamics characteristics and oxyproline content of PMF. The structural changes of PMF were observed under light and electron microscope respectively.       Results      Three dogs died. The body weight and foodintake had no statistical difference between two radiotherapeutic groups. In the early days of radiation

mild flare and congestion in esophagoscopy were found both in esophagus and flaps

a little hair growing in flaps. No anastomotic stenosis. No significant deviation was found in the compliance of PMF stoma

vitodynamic characteristics and the oxyproline content of PMF in the three groups of dogs. Light and electron microscopy showed that except that the alignment of PMF collagen was more disordered and larger than cervical skin wounds

no more structural changes was found after radiation.        Conclusion      Platysma myocutaneous flaps after esophageal reconstruction in dogs might tolerate radiotherapy with usual dose.