Abstract: Objective: To investigate the value of multi-slice CT in the diagosis of pulmonary laceration. Methods: The CT data of the first examination and reexamination after treatment in 25 cases with pulmonary laceration were analyzed retrospectively. Results: Fortyseven lesions in 25 patients were found,which included 7 lesions of traumatic gas cyst,35 lesions of gas-fluid cyst and 5 lesions of fluid cyst complicated with various degree pulmonary contusion around the lung laceration in CT finding. The CT dynamic observation in 21 patients showed that the gas cyst lesions could change to gas-fluid cyst or fluid cyst,and the gas-fluid cyst lesions could change to fluid cyst,no reverse evolution lesion was found. Conclusions: Multi-slice CT examination is the best way to diagnose pulmonary laceration and dynamic observation has important value for clinical treatment.