After a busy summer vacation, the hectic pace of the ward eased as the children returned to school. During this vacation, I was impressed by several children, all boys, with posterior maxillary sinus polyps. The incidence of this disease is not high, the following on this disease will be my understanding of the pathogenesis of the disease and treatment experience a brief introduction, for reference only, in order to guide the medical treatment and understand how to avoid recurrence. This disease occurs in adolescents, according to the literature is similar to the incidence of men and women, I was treated by the boys are common, ranging from 7 to 13 years old, otorhinolaryngologists according to the following conditions is very easy to diagnose. 1, the posterior nostril polyp is unilateral, the main symptom is unilateral progressive nasal congestion, nasal discharge, not much. If the polyp prolapses from the middle nasal passage to the nasopharynx, it will lead to bilateral nasal congestion, open-mouth breathing, and snoring in sleep. 2, nasal endoscopy can be seen on one side of the middle nasal tract source lychee meat-like new organisms to the posterior nostril prolapse to the nasopharynx, from the opposite side of the posterior nostril can also be seen in the nasopharynx lychee meat-like new organisms. 3, now routinely need to carry out nasal CT examination, CT shows the affected side of the maxillary sinus, the affected side of the middle nasal tract, nasopharynx is full of soft tissue density shadow Pathogenesis and pathological changes: the etiology is not yet clear. Polyps originate in the maxillary sinus and then enter the nasal cavity through the sinus opening of the maxillary sinus in the middle nasal passage with an elongated stemmed tip, sliding backward into the posterior nostril and may protrude into the nasopharynx.Stammberger (1986) found that polyps originated in the maxillary sinus cavity in the upper inner corner of the sinus near the sinus opening using nasal endoscopy. Kamel (1990) borrowed endoscopy in 22 cases of posterior nostril polyps found that 13 cases originated from the medial wall of the maxillary sinus, and the other 9 cases were difficult to determine the location of the origin due to the extensive mucosa of the sinus wall.Berg (1988) found that the polyp was connected to the sinus wall cysts in the sinus cavity through the maxillary sinus probing of 15 cases of posterior nostril polyps, and he therefore believed that the origin of posterior nostril polyps was from the cysts of the sinus wall of the maxillary sinus, and that the cysts were gradually growing and entering the nasal cavity through the sinus opening. The cyst gradually increases in size and protrudes into the nasal cavity through the sinus opening, eventually forming a posterior nostril nasal polyp. Treatment principle: Since the origin of adolescent posterior nostril polyp is especially in the maxillary sinus, then the operation can not only remove the polyp tissue in the nasal passages and nasopharynx, but also completely remove the lesions in the sinus in order to avoid recurrence. Failure to remove the intra-sinus lesions completely and recurrence is certain and within a very short period of time. Before the application of nasal endoscopy in the clinic, the nasal part can be pulled out by strangling its tip with a loop device, and then resecting the sinus lesion by the way of Cole-Luke’s surgery (maxillary sinus inferior nasal opening) is the usual surgical way, and the best minimally invasive surgical way is to remove the sinus lesion by the way of endoscopic polyp resection and enlargement of the natural opening of the maxillary sinus through the middle nasal passage since the application of the nasal endoscopy.