Abstract: Objective To study the therapeutic effect of percutaneous microwave ablation（PMWA） on liver cancer and its complications. Methods One hundred and seventy-one liver cancer patients（274 nodules with a maximum diameter of 0.9-5.7cm and a mean diameter of（2.3±0.9）cm）,143 hepatocellular carcinoma（HCC） patients（234 nodules）,and 16 metastatic liver carcinoma（MLC） patients（15 nodules） were treated with ultrasound-guided PMWA.Single point ablation was applied for nodules with their diameter≤1.7cm and multipoint ablations were applied for those with their diameter ＞1.7cm.The patients were regularly followed up for 2-26 months after treatment,during which local tumor progression was found in the original foci or their surrounding areas. Results The mean PMWA time was（474.0±228.0）s for a single lesion.CT,contrast-enhanced ultrasound or MRI showed no enhanced manifestations in 261 nodules or at their margins and enhanced manifestations in 13 nodules or at their margins 1 month after PMWA,with an effective rate of 95.3%（261/274）.The incidence of local tumor progression was 8.8%（24/274） during the 2-26 months follow-up period.The incidence of major complications was 1.1%（3/274）,including liver abscess in 1 patient which was cured after antibiotic treatment with a dwelling tube,edema and mildly-thickened gallbladder wall in 1 patient,and infection adjacent to the liver margin below the ablation area.No severe injury and death occurred due to PMWA. Conclusion PMWA is a safe and effective procedure for liver cancer and its complications.