Abstract: Objective: To explore the value of fine needle aspiration cytology in diagnosis of space- occupying lesions of lung. Methods: A total of 165 samples were obtained by CT-guided percu-taneous paracentesis, and their cytology and histopathology data were observed and analyzed retrospec-tively. Results: Of the 165 cases, 160 were distinctly diagnosed by cytological observation alone or with the assistance of histopathology. The diagnostic accuracy rate of malignant space-occupying lesions of the lung was 95.5% and that of benign lesions was 96.8%. Conclusions: CT-guided percutaneous para-centesis is safe and site-specific. Cytology or cytology combined with histopathology is very valuable todiagnose space-occupying lesions of lung.