PURPOSE: To compare the efficacy and safety of ultrasound guided automated gun biopsy with fine needle aspiration biopsy of focal liver lesions. MATERIALS AND METHODS: We performed 32 automated gun(19.5G Autovac Biopsy Needle) biopsies and 27 fine needle aspiration(22G Westcott Style Biopsy Needle) biopsies in 48 patients with malignant focal liver lesion under the guidance of ultrasound. We compared the "positive for malignancy rate" and "pathologic diagnosis rate" of both methods with final diagnosis, and the rate of complications. RESULTS: The "positive for maiignancy rate" of automated gun biopsy and needle aspiration are 84.4%(27/32) and 66.7%(18/27) respectively(p=0.11). The "pathologic diagnosis rate" are 84.4%(27/32) and 55.6%(15/27) with significant statistical difference(p<0.05). And there is no difference of the rates of significant complications. CONCLUSION: When compared with the fine needle aspiration biopsy, ultrasound-guided automated gun biopsy is safe and more effective method for malignant focal liver lesion.