The clinical data of two adolescents with unilateral nasal cavity neoplasm were analyzed. Both were male, one was 14-year-old and the other was 17. Both were complained of unilateral nasal obstruction and nasal discharge; The course of disease of the former was one month ,and that of the latter was three month; both were found neoformation in unilateral nasal cavity in medical examination. Occupying lesion in unilateral nasal cavity and sinus were demonstrated in CT scan of two cases. Endoscopy surgery were operated in both cases, incisal opening in labiogingival groove was added in the latter. Pathology of the former was capillary hemangioma and the latter was rhabdomyosarcoma. No findings indicating recurrence has been observed in two cases under 6 months follow-up. Recognition at nasal cavity and paranasal sinus neoplasm in adolescent is essential so that proper management can be initiated.