Objective To explore the effectiveness and appropriate energy parameters of high-intensity focused ultrasound (HIFU) in treating infant hemangiomas. Methods Between January 2009 and September 2010, 60 infants with hemangioma were treated. There were 23 boys and 37 girls, aged from 3 to 30 months with an average of 10 months. These hemangiomas were located at head and face (24 cases), trunk (15 cases), l imb (16 cases), buttocks (2 cases), perineum (1 case),and multiple lesions (cervix, abdomen, and upper l imbs, 2 cases). The size of hemangiomas ranged from 0.8 cm × 0.6 cm to 6.0 cm × 5.0 cm. The 60 infants were randomly divided into 3 groups: groups A, B, and C (n=20) based on different ultrasound energies used in treatment. The lesion surface was irradiated with 3-5 mm/second for 5 continuously by ultrasonic therapeutic apparatus at a frequency of 9 MHz, impulse of 1 000, and 10% of scanning overlap; the powers of 3.5, 4.0, and 4.5 W were used in groups A, B, and C, respectively, 3 times as a course of treatment with 1 month interval. The effect and ulcer and scar risk in irradiation region were observed after 6 months of treatment. Results All cases were treated for one course. After 6 months of treatment, no significant difference in the effect was found among 3 groups based on hemangioma treatment judging criterion (P gt; 0.05). Neither ulcer nor scar occurred in group A; ulcer occurred in 4 cases (20%) of group B with superficial scars, and in 7 cases (35%) of group C with obvious scars. The rates of ulcer and scar in groups B and C were significantly higher than that in group A (P lt; 0.05). Conclusion HIFU irradiating is one of effective methods for treating infant hemangioma, but the appropriate energy was below 3.5 W.