This is a multi-national, multi-center, randomized, double blinded, parallel-group study to assess the Immunogenicity and safety of NBP608 compared to varivax which are indicated for active immunization for the prevention of varicella. Total of 488 subjects of 12 months to 12 years of age are enrolled, and each subject is administered with single dose of vaccine which is randomly assigned in 1:1 ratio. Stratified randomization for age group is used to achieve the balance of treatment assignment within age strata.