Objective To explore the value of clinical features combined with 3-D reconstruction of multi-slice spiral CT in diagnosis of foreign body in trachea or bronchus in children. Methods The data of 52 children diagnosed of foreign body in trachea or bronchus were retrospectively reviewed. Both clinical features and 3-D reconstruction of multi-slice spiral CT were analyzed and summarized. Results In 52 children included ( 35 males and 17 females), 82 . 7%were under 3 years old. 30 children has repeated coughing and wheezing as the principal manifestation while 22 children presented with burst irritating and cough as primary manifestation. The main clinical signs were the asymmetry of pulmonary respiration ( 43 cases), wheeze ( 32 cases) and moist rale ( 29 cases). The positive rate of 3-D reconstruction of multi-slice spiral CT was 100%and consistent with the results of surgery. Among them, 5 cases were embedded in the trachea, 27 cases in the right bronchus, and 20 cases in the left bronchus. The main complications were emphysema ( 38 cases), bronchitis and pneumonia (32 cases), and pulmonary atelectasis (5 cases). Conclusion The combination of clinical features and 3-D reconstruction of multi-slice spiral CT can provide a reliable basis for the diagnosis of foreign body in trachea or bronchus in children.