Purpose : To compare the efficacy and safety of ultrasound guided automated gun biopsy with fine needleaspiration biopsy of focal liver lesions. Materials and Methods : We performed 32 automated gun(19.5G AutovacBiopsy Needle) biopsies and 27 fine needle aspiration(22G Westcott Style Biopsy Needle) biopsies in 48 patientswith 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 malignancy 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 significantstatistical 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 moreeffective method for malignant focal liver lesion.method for malignant focal liver lesion.