Microwave coagulation therapy (MCT) for liver tumors had initially developed in Japan and now is spreading worldwide. Microwave thermosphere ablation is a new concept using cooling antenna to create a larger spherical necrotic area. Recently, the indications of MCT is spreading from hepatocellular carcinoma to liver metastases. MCT is recommended only for patients with unresectable colorectal liver metastases (CRLM); ≤ 3cm and ≤ 3 nodules in combination with systemic chemotherapy. MCT has some benefits compared with radiofrequency ablation: 1) Shorter ablation time; 2) Lower local recurrence rate; 3) better disease-free and overall survival; 4) Complete necrosis even for the tumor adjacent to the large vessels; and 5) Similar complication rates. In summary, MCT is evolving as one of the promising local treatments for liver metastases; however, a randomized control trial is required to create solid evidences.