Objective To improve the recognization of the cavitating lung cancer in CT scans.Methods From May 1996 to June 2000,37 patients out of total 271 primary lung cancers were confirmed by transthoracic needle aspiration biopsy,operation and pathlogical examination.Results There were 5 pattens cavitaties in the CT manifestations.They were 15 cases cavities with thick irregular walls,14 cases round or ovoid growths with central or eccentric cavitation,4 cases solid lobes containing cavities,2 cases thin-walled cavities resembling cysts and 2 cases fissural cavities.There were 24 cases squamous-cell carcinomas,5 cases adenocarcinomas,2 cases small-cell carcinomas,2 cases alveolar-cell carcinomas.Conclusion The cavitating lung cancer is made misdiagnosis easilier.There is important clinical value in diagnosis with transthoracic needle aspiration biopsy(TNAB).