Abstract: 【Abstract】 Microfocused ultrasound （MFU）, as a new approach for facial skin tightening and lifting, has been widely applied in recent years. Its action mechanism is that heat can be transmitted to the deep dermis and superficial musculoaponeurotic system through precise and depth-consistent microcoagulation zones, leading to the contraction and remodeling of skin collagen without damage to the epidermis. MFU has high safety with few serious adverse reactions. However, there are still doubts whether it can lead to subcutaneous scar formation, the risk of lipolysis, or nerve, vessel and eye injuries, etc. Appropriate use and selection of patients can minimize the occurrence of these rare adverse reactions as much as possible.

Key words: Ultrasonic therapy, Subcutaneous tissue, Facial tightening, Adverse reaction