Objectives : To research the recent trends of study related to pain modulation of acupuncture. Methods : We searched the resent study related to pain modulation of acupuncture. Results & Conclusion : 1) Early studies demonstrated that the analgesic effects of acupuncture are mediated by opioid peptides in the periaqueductal gray. Recent evidences show that nitric oxide plays an important role in mediating the cardiovascular responses to acupuncture stimulation through gracile nucleus-thalamic pathway. 2) Recent evidences show that acupuncture stimulate gene expression related to pain. 3) By using functional magnetic resonance and positron emission tomography, recent study suggest that acupuncture has regionally specific, quantifiable effects on pain-relevant brain structures.