The work is to report an ,in vivo, experimental study on metal stent-caused damages to esophageal mucosa of pigs under radiofrequency hyperthermia Five points were located for observation, i.e. the middle of the stent, the exit of the stent, 2cm and 4cm under the exit and 4cm above the exit. The stent were placed in esophageal mucosa of 13 pigs and were heated by SR-1000 radiofrequency hyperthermia machine. The esophageal mucosa were observed with naked eyes. And optical microscopy was used to understand the variety of the esophageal mucosa The esophageal mucosa of four temperature checkpoints and observation point were smooth, moist and pale, without any bleeding, erosion and ulcer, while the squamous epithelium of esophageal mucosa of each observation point was normal, with no statistical significance for differences in both the observation results (,p,>,0.05). Therefore, influence of the metal stents on esophageal mucosa could be neglected in radiofrequency hyperthermia. It is safe and feasible to carry out radiofrequency hyperthermia on esophagus placed metal stent.