With approval of more COVID-19 vaccines for children, vaccine attributes may influence parental acceptance and choices. We aimed to assess effects of vaccine attributes and information on herd immunity on childhood COVID-19 vaccine acceptance. A survey experiment was conducted with caregivers of children aged 6 months to 11 years old and health care workers (HCWs) in China from September 14 to November 18, 2021. Respondents were randomly assigned to receive differing information on herd immunity (> 80% of the entire population must be vaccinated; or no information). Respondents then completed eight discrete choice tasks to assess vaccine acceptance based on attributes. 2331 (90.07%) of 2588 surveyed caregivers and 1576 (92.71%) of 1700 surveyed HCWs would accept COVID-19 vaccination for children, respectively. High Odds Ratios (OR) were found for acceptance of a vaccine with 90% over 50% efficacy (OR 6.70 [95% CI 6.11-7.35] for caregivers; 11.44 [10.12-12.95] for HCWs); and risk of adverse reactions to be 1 over 10 in 10,000 (3.96 [3.72-4.22] for caregivers; 2.98 [2.76-3.22] for HCWs). To achieve herd immunity target (> 80% vaccination coverage), vaccine efficacy should reach over 70% and risk of adverse reactions lower than 1 in 10,000. Knowledge on herd immunity target increased the odds of vaccine acceptance (1.82 [1.34-2.46] for caregivers; 2.42 [1.58-3.72] for HCWs). Childhood COVID-19 vaccine acceptance was high in China, independent of child's age, and depended on vaccine attributes.