This pilot study aims to evaluate the safety and efficacy of hemoporfin photodynamic therapy (PDT) with different light doses for port-wine stain (PWS）in 2-7 years old children. The pharmacokinetic behavior and pharmacokinetic parameters of hemoporfin in children will be investigated as well.

Inclusion Criteria:

• Children with clinical diagnosis of PWS；
• ≥2 years old and <7 years old；
• The guardians agreed to voluntarily participate in this study and signed the informed consent agreement

Exclusion Criteria:

• Therapy area located outside of head and neck;
• Other skin diseases that might interfere with the efficacy evaluation;
• Patients with respiratory disease, severe pulmonary dysfunction, history of airway hyperresponsiveness, or family history of suspected malignant hyperthermia;
• Preexist scars in the treatment area caused by previous treatment, which might interfere with the efficacy and safety evaluation;
• with allergic diseases; known to be allergic to eggs, milk or soy protein; known to have skin photoallergies, porphyria or known allergic history of experimental drugs (porphyrins) and chemically structure similar drugs; known allergic history of anesthetics; allergic constitution;
• Cicatricial constitution;
• Immunocompromised conditions or need long-term use of glucocorticoids and immunosuppressive agents;
• Electrocardiographic abnormalities or organic heart diseases;
• Hepatic or renal functions abnormal (alanine aminotransferase or aspartate transaminase or total bilirubin > 1.5 upper limit of normal [ULN], or serum creatinine or blood urea nitrogen > 1.5 ULN);
• Coagulation disorders;
• Patients with severe neurological, psychiatric, endocrine and cardiovascular diseases; with epilepsy history or recent epileptic seizures;
• Be evaluated not suitable for anaesthesia by risk assessment before anaesthesia；
• Previous therapy of PWS within the last 4 weeks;
• Participation in any clinical studies within the last 4 weeks;
• Be judged not suitable to participate the study by the investigators