Abstract: Objective　To investigate the clinical significance of narrow-band imaging (NBI) system in the diagnosis and treatment of Peutz-Jeghers syndrome (PJS) in children. Methods To retrospectively summarize the clinical data of 15 cases diagnosed with PJS, and compare with 70 cases diagnosed with juvenile polyp. And all of the polyps were further diagnosed with pathological examination and the histological type should be analyzed.The polyps of 15 children with PJS were diagnosed with the white light imaging (WLI) and the NBI system, respectively. The pit patterns of various polyps was observed with NBI. We made a comparison between the sensitivity and specificity of NBI and WLI in diagnosis of adenomatous polyps. Result 76 lesions in 15 cases were detected by the WLI and NBI system,including adenomatous polyps (12) and harmatoma (64) which were further diagnosed by pathological examinations.By using the NBI system,69.7% (53/76)PJS polyps (pit patterns)were diagnosed as type Ⅰ and 27.6% (21/76) PJS polyps were diagnosed as type Ⅱ or Ⅲ .By using the NBI system，the sensitivity and specificity for diagnosing PJS polyps were 83.3% (10/12)and 98.4％ (63/64)，which were obviously higher than those by using the WLI system (P<0.05). Conclusion Observation of pit patterns of polyps by the NBI system can help predict the pathological changes of PJS polyps.By using the NBI system,the sensitivity and specificity of the diagnosis of adenomatous polyps are higher than those by using the WLI system.It has guiding significance to choose the method to remove a polyp.