Result the subtypes and effectiveness of functional endoscopic sinus surgery(FESS) using a microdebrider Introduction: Chronic rhinitis in children has been on the rise in recent years, and polyps account for the majority of benign nasal cancers in children. Surgery is necessary when drug treatment is ineffective. We use pediatric rhinoplasty. Aimed at calculating the subtypes and effectiveness of Functional endoscopic sinus surgery(FESS) using a microdebrider. Material and methods: The survey was conducted between March and April 2020, based on the Otolaryngology Surgery Department of the National Center for Maternal and Child Health, using the cross-section of analytical design under Objectives 1 and 2 and the longitudinal design under Objective 3. Under Objectives 1 and 2, participants' information was collected from a pre-prepared questionnaire from their medical history. The questionnaire has four chapters that provide general information about the patient, clinical signs, surgical structure, and biopsy results. The pain was assessed by the “Sino-Nasal Outcome Test (SNOT-20)”. A total of 98 patients were included in the statistical analysis of the survey results using the STATA 15.0 program, and the results of the surgery were evaluated by 20 patients. Results: In children with chronic rhinitis, the SNOT20 test showed a statistically significant difference of 1.6 ± 0.6 before surgery and an average of 0.51 ± 0.11 after surgery. Conclusion: In chronic rhinitis, FESS with microdebrider surgery is an effective treatment for children.