The injection of lines, clinically known as lines filler, refers to the treatment plan of autologous fat or hyaluronic acid filling in the bilateral lines depression, with the possibility of side effects such as allergy, edema, infection and embolism. Filling of lines refers to the supplemental capacity to fill up the depressions in the lines by localized injections of autologous fat and hyaluronic acid. These treatments are invasive and carry the risk of acute complications, early complications, and long-term complications. 1. Acute complications usually appear within 72 hours after injection, including transient erythema, edema, itching, hardness, ecchymosis, embolism, rapid-onset hypersensitivity reactions, etc. Embolism is particularly serious among acute complications, and regional small vein embolism can lead to local tissue ischemia and necrosis, while arterial embolism may lead to embolism of important intracranial vessels. 2. Early complications usually appear a few days to weeks after the injection, including local infection, recurrence of herpes, skin necrosis due to vascular embolism, rigidity of expression, and persistent erythema; 3. Distant complications include displacement of filler, scarring due to infection or tissue necrosis, foreign body granuloma, etc. The filler of legal lines requires very high professional and technical requirements for the operator, and it is recommended that patients with treatment needs go to regular medical institutions to regulate the treatment after the interview, so as not to cause adverse consequences.