Abstract: Objective: To evaluate the clinical application value of percutaneous lung biopsy by improved CT fluoroscopy.Methods: Forty-four cases were analyzed percutaneous lung biopsy by improved CT fluoroscopy which were proved by operation or pathology with the puncture needle.The main points are:choose the best layer,point,angle,depth,draw and obtaining at many points.Results: All 44 lung lesions were successfully conducted biopsy through CT-guided fine needle aspiration,and the pathological confirmed diagnosis rate was 98%,pathological diagnosis 31 malignant tumors and 13 benign tumors.Conclusions: The pereutaneous lung biopsy by improved CT fluoroscopy is accurate,less of complication.It is a safe,effective,simple and practical way for diagnosing lung diseases.