EV (electric vehicle) charging scheduling to maximize the revenue of charging station while satisfying customer demands is challenging, mainly due to the time-varying nature of user demands and profits. In this paper, we develop an admission control and scheduling mechanism to jointly consider the revenue of charging stations and the service requirements of customers. We consider an offline setting. Given a set of inflexible service demands from customers, our objective is to design an admission control and scheduling scheme, so that the admitted demands can be satisfied while the revenue of the charging station is maximized. We first propose a calculus based scheduling algorithm, and show that if the system is underloaded, it maximizes the revenue of the charging station. We then consider the general overloaded case, and prove that it is NP-complete. We then develop a heuristic algorithm to greedily decline a subset of demands until the remaining demands can be satisfied. We evaluate the performances of the proposed algorithms through simulations.