Objective To explore the CT features of pulmonary lymphangiomyomatosis (PLAM).Methods Clinical and high resolution CT (HRCT)data of 14 patients with pathologically proved PLAM were analyzed retrospectively.The clinical and CT features were summarized by combining the literatures.Results All 14 cases were female.They all presented with dyspnea in different degree after the activity. Scattered or widely distributed translucent and cystic lesions with indistinct walls in bilateral lungs were seen on routine CT images. HRCT showed homogeneous clear thin-walled cysts with diameter ranging from several millimeters to 25 mm,wall thickness of 1-2 mm,and surrounded by normal lung tissue.Meanwhile,blood vessels were found around the cysts,and there were no central lobular cores.The cysts were different sizes and irregular distribution.6 patients had extra-pulmonary CT manifestations:1 case with intracranial multiple sclerosis, hepatic and renal angiomyolipomas,and hepatic multiple hemangiomas,3 cases with mediastinal,hepatic and renal angiomyolipomas, and 2 cases with retroperitonea lymphangioleiomyomatosis.Conclusion The CT of PLAM is characterized by the diffuse distribution of thin-walled cystic cavities and the wall thickness is generally uniform.The typical manifestations of HRCT combined with clinical data have great values in the early diagnosis and differential diagnosis.