The nasolabial folds are a surface marker of the human face, and everyone has them, the depth of which varies with individual differences. The nasolabial folds are a shallow furrow from the sides of the nose to the outer corners of the mouth, with the upper end starting at the top, then going down to the bottom, and then going down between the cheeks and lips, so it is commonly called “lip and face furrow”. This furrow is only obvious in children and young people when they smile, and it is also obvious when the face ages. The diagnosis can be confirmed by nasal endoscopy. The nasal endoscope is a rigid endoscope with a cold light source with sufficient light, and through the mirror image magnification, the anatomical structure from front to back can be clearly observed deep into the nasal cavity, and nasal surgery has changed from a blind empirical operation to one that focuses on the protection of normal structure and physiological function. The endoscopes commonly used in clinical practice are 0°, 30° and 70°, with a diameter of 4.0mm and a body length of 180mm, which have a large field of view and good brightness. Children can use 2.7mm diameter endoscope. Cold light source and light source wire should also be available. In order to do some simple operations, the following instruments should also be prepared 0 ° and 45 ° sieve sinus forceps, straight suction tube, curved suction tube, maxillary sinus trocar puncture needle, maxillary sinus biopsy forceps, butterfly sinus bite forceps, etc. If there is a video recording system to help operation, teaching and data preservation, all nasal hair should be clipped before the examination. Examination procedure: (1) The patient is placed in a sitting or sloping position with the head tilted toward the examiner, routine nasal and facial disinfection, and sterile towels are laid. (2) Do surface anesthesia of the nasal mucosa and constriction of the mucosal vessels with 1% dicaine ephedrine cotton tablets. (3) Apply a 0° endoscope to enter through the nasal floor or (and) the inferior nasal tract, and observe the anterior inferior turbinate, middle and posterior inferior turbinates, nasal septum and inferior nasal tract from anterior to posterior. The 30° endoscope is used to enter from the base of the nose to the posterior nostril, and the posterior edge of the nasal septum is used as a marker to gently turn the mirror to observe the lateral wall of the nasopharynx and the opening of the eustachian tube, paying attention to the rounded pillow of the eustachian tube and the pharyngeal fossa, and the endoscope is gently withdrawn to the upper surface of the inferior turbinate to observe the middle turbinate and the middle nasal tract, paying attention to the hook, sieve bubble and sieve funnel; the mirror is continued to enter along the lower edge of the middle turbinate, and when it reaches the posterior end of the middle turbinate, the mirror is turned outward When the posterior end of the middle turbinate is reached, the mirror is turned outward by 30°-45° to observe the septal fossa and the opening of the pterygoid sinus. The 70° endoscope is applied to enter from the nasal floor straight to the posterior nostril to observe the top of the nasopharynx, then the endoscope is withdrawn and the inferior turbinate surface is used as a support to enter the mirror from the inferior edge of the middle turbinate to find the posterior end of the middle turbinate, turn the mirror outward and look for the opening of the maxillary sinus from the posterior aspect of the middle nasal tract forward; if the middle turbinate is well contracted and has a space with the nasal septum, the 70° endoscope is applied to enter between the middle turbinate and the nasal septum and the superior turbinate can be observed with the superior nasal tract, and a few people can also see the uppermost turbinate and the uppermost nasal tract. During nasal endoscopy, attention should be paid to the presence of congestion, edema, dryness, ulceration, bleeding, vasodilation and neoplasia in the mucosa of the nasal cavity and nasopharynx; the primary site, size and extent of neoplasia and the source of purulent secretions should be noted; in case of suspected neoplasia, biopsy should be taken, and the purulent secretions in the sinuses can be aspirated and sent for bacteriological examination.