Objective To evaluate the value of power Doppler and contrast-enhanced ultrasonography in the detection of tumor after microwave tissue coagulation (MTC). Methods Ultrasound Microwave Theraphy-1 (UMT-1) equipment was used,and a 9 mm length antenna was inserted directly into the tumor at laparotomy in 10 VX 2-bearing rabbits. The energy output was 60 W?120 s per bout. Two-dimensional, power and contrast-enhanced (Levovist, 300 mg/ml, 0.3 ml/kg) imaging was performed pre- and post-treatment. Pathology examination was applied in contrast. Results Along the needle being narrow hyper echoic imaging, broad-equable hypo echoic imaging was observed around the center after MTC immediately and the edge of tumor was unclear. Intratumoral blood flow was observed in 4 VX 2 tumors with power ultrasonography while there was enhanced-signal in 10 VX 2 tumors using contrast-enhanced ultrasonography. These tumors were confirmed incomplete necrosis by pathology. Conclusions Contrast-enhanced power Doppler ultrasonography shows more sensitive in assessing the therapeutic effect of microwave on VX 2 tumor. Residual tumor can be seen as persistent color enhancement by using contrast-enhanced ultrasonography.