Objective To study the effect of percutaneous CT-guided lung biopsy on the patients with peripheral lung focus.Methods Percutaneous CT-guided lung biopsy was performed in 38 patients with peripheral lung focus who were admitted to the Affiliated Hospital,Armed Police Medical College from Feb.2002 to Jan.2005.Results A total of 38 patients were studied,including 30 patients with lung cancer,2 patients with pulmonary tuberculosis,5 patients with benign pulmonary diseases and 1 patient with negative result.The positive rate was 97.36% in the 38 cases with a slight side effect.Conclusion This method is simple,safe and effective,and it is very important in diagnosis of patients with peripheral lung focus.