The Korean Early Childhood Education and Care Panel Study (K-ECEC panel study), commencing in 2021, aimed to collect data related to early life growth and development. In particular, based on Bronfenbrenner’s ecological model, the study aims to collect intrinsic and extrinsic parental factors, educational and caregiving experiences in institutions, and environmental factors from the prenatal stage through infancy, toddlerhood, and early childhood. This is important for understanding child development with varied dimensional aspects. The K-ECEC panel study uses a stratified sampling strategy in order to recruit pregnant women based on regions and numbers of deliveries to individual hospitals. This resulted in the participation of 3,372 women, 95 of whom were from low-income families and 72 from multicultural families. The K-ECEC panel study is based on a household survey collecting information related to pregnancy, birth, and childrearing. The survey included an annual follow-up for individual households of newborns from 2022, and the second round of the survey was conducted in 2023. A total of 2,775 children participated in the first round of the survey, 1,423 of whom were boys. As there are few birth cohort studies considering policy-oriented aspects in Korea, the K-ECEC panel study is expected to provide data to understand childhood trajectories for growth and development. Furthermore, in terms of childcare and education, it is expected to be utilized to evaluate the policy effects of early life and parenting support.