The purpose of this paper is to evaluate the impact of state government`s regulation on the supply of childcare in the United States. There are controversies among scholars whether government regulations would constrain the supply of childcare centers. The major reason scholars do not reach agreement on the issue is lacking the empirical evidences. To examine the regulation impact on the supply childcare, I focus on critical licensing regulations-staffing requirements, and education/training requirements-on child care centers. The state level data is collected and the model is estimated by Weighted Least Square (WLS). What I find is that state regulations on childcare licensing do constrain the supply of childcare centers. In particular, state staffing requirements, child to staff ratio and total children size in a childcare center, have critical impact on the supply. Interesting finding is that total children group size that is neglected in previous studies does constrain the supply of childcare centers. Another new finding is that the critical burdens for childcare providers are requirements for education and training of teachers but not of directors.