Mobile payment is the killer application in mobile commerce. We classify the payment methods according to several standards, analyze and point out the merits and drawbacks of each method. To enable future applications and technologies to handle mobile payment, we provide a general layered framework and a new process for mobile payment. The framework is composed of load-bearing layer, network interface and core application platform layer, business layer, and decision-making layer. And it can be extended and improved by the developers. Then a pre-pay and account-based payment process is described. Our method has the advantages of low cost and technical requirement, high scalability and security.