Introduction: No research on clinical diagnoses of meniscus tears. Purposes: (1) To describe clinical features, MRI of meniscus tears due to knee trauma and (2) To demonstrate types of traumatic meniscus tears observed in knee arthroscopy. Methods: Retrospective study of 41 patients suffered from knee arthroscospy. Results: Reasons for meniscus tears: sport injury (36.6 percent), traffic acddents (26.8 percent). Symptoms: knee pain 92.6 percent, joint tenderness (75.6 percent), joint-space pain as pressed (82.9 percent), Mac Murray (56.1 percent). Sensitivity of MRI 79.5 percent
reliability 66.7 percent. Medical meniscus tear (51.2 percent) lateral meniscus tear (36.6 percent) and both 12.2 percent. The tears turn out to be mainly at posterior horn (36.6 percent) and vertical tears account for 41.9 percent. Conclusions: Meniscus tears may be early recognized on clinical diagnosis and MRI to draw the optimal medical treatment.