The Real-Time Programming language is considered as system description language with temporal constraints.There are shortcomings in the temporal mechanism of existed language.So,The paper presents the RTS/Java Real-Time language based on Java to solve the mapping from TGM model to RT-Actor model.The language defines the RTS/Java class,method and their constraints,and designs the method innovation mechanism.The mechanism has solved Allen's temporal constraints.RTS/Java language succeeds in describing the real-time simulation system of three surveillance satellites.RTS/Java features:(1) explicitly expressing temporal constraint,(2)temporal constructs illustrating task's period,(3)temporal logic independent of computer hardware,(4)the pure Object-Oriented style,multi-front-end sharing resources.