A propositional projection temporal logic (PPTL) based model checking approach for rate monotonic scheduling (RMS) is presented. With this approach, RMS controlled systems are modeled by PROMELA, which is the system modeling language in model checker SPIN. The desired property is specified by a PPTL formula. Next, whether or not the system satisfies the property can be verified with SPIN. Accordingly, the schedulability of a group of tasks can be obtained; meanwhile, other properties of the tasks scheduling system under RMS algorithm can also be verified.