The study aimed to assess the determinants of immunization coverage in children born in 2008-2009, living in Zhejiang Province. The World Health Organization’s cluster sampling technique was applied. Immunization coverage of 5 vaccines was assessed: BCG vaccine, diphtheria and tetanus toxoids and pertussis vaccine, poliomyelitis vaccine, hepatitis B vaccine, and measles-containing vaccine. Determinants for age-appropriate immunization coverage rates were explored using logistic regression models. Immunization coverage of 5 vaccines were all greater than 90%, but the age-appropriate immunization coverage rates for 3 months and for first dose of measles-containing vaccine was 41.3% and 64.5%, respectively. Siblings in household, mother’s education level, household registration, socioeconomic level of resident areas, satisfaction with clinical immunization service, and convenient access to local immunization clinic were associated with age-appropriate coverage rates. Age-appropriate immunization coverage rates should be given more attention and should be considered as a benchmark to strive for in the future intervention.