Scenario has been used to describe agent behaviors in the context of environment situations in the specification languages for agent-based systems, such as SLABS. It becomes an important language facility in the declaration of an agent for specifying its behaviors in its environment. Therefore, towards agent-oriented programming, it is necessary to introduce and implement scenario mechanism in programming languages. This paper reports our attempts to support the language facility from the view of programming languages, and presents an approach to facilitating the scenario mechanism in agent-oriented programming. The basic idea is to extend object-oriented programming language to support agent-oriented programming, where Java is chosen as the base language. Firstly, the language framework of agent-oriented programming, SLABSp is presented, mostly conforming to SLABS, whose syntax is extended based on Java. Scenario mechanism is introduced as the new feature in the programming language. Secondly, the underlying object models are defined to serve as the semantics of the language, where agents are modeled by a couple of objects. A compiler has been built to compile the agent-oriented programs into Java. A running platform has been constructed as the multi-agent runtime environment of SLABSp.