A moirésuperlattice formed in twisted van der Waals bilayers has emerged as a new tuning knob for creating new electronic states in two-dimensional materials. Excitonic properties can also be altered drastically due to the presence of moireṕ otential. However, quantifying the moirépotential for excitons is nontrivial. By creating a large ensemble of MoSe 2 /MoS 2 heterobilayers with a systematic variation of twist angles, we map out the minibands of interlayer and intralayer excitons as a function of twist angles, from which we determine the moireṕ otential for excitons. Surprisingly, the moirépotential depth for intralayer excitons is up to ∼130 meV, comparable to that for interlayer excitons. This result is markedly different from theoretical calculations based on density functional theory, which show an order of magnitude smaller moirépotential for intralayer excitons. The remarkably deep intralayer moirépotential is understood within the framework of structural reconstruction within the moiréunit cell.