The purpose of this study is to observe the persistence of protection, duration of protection, safety and breakthrough infection rates afforded by live attenuated varicella vaccine in children over a 5-year period.

Inclusion Criteria:

• Participant are healthy children aged 1-6 years, who has inquired for medical history and physical examination, and met the requirement of the vaccine trial
• Parent/legal acceptable representative is willing and able to understand the protocol requirements and provide informed consent
• Subject and parent/guardian able to attend all scheduled visits and comply with all trial procedures
• Body temperature ≤37℃

Exclusion Criteria:

• Participant with previous history of chickenpox or zoster
• Receipt of varicella vaccine
• Reported the family history of allergies, convulsions, epilepsy and mental illness
• Known allergy to any constituent of the vaccine
• Known serve illness, in a fever, acute infection and chronic disease activity
• Receipt of steroid
• Reported the history of thrombocytopenia or other coagulation disorders, which may cause
• Known or suspected impairment of immunologic function, or receipt of immunosuppressive therapy or immunoglobulin since birth
• Known congenital malformation, developmental disorders and severe chronic disease (e.g. Down's syndrome, diabetes, sickle cell anemia and neurologic disorders)
• Known dermatopathy with allergy, herpes, fester, and fungal infection
• Receipt of whole blood, blood plasma or immunoglobulin in the 3 months preceding the trial vaccination
• Reported the history of acute illness had need systemic antibiotics or anti-viral treatment of infections in the 7 days preceding the trial vaccination
• Participant with fever(temperature≥ 38℃) in the days
• Any condition, which, in the opinion of the investigator, would pose a health risk to the subject