This paper proposes a XML based Agent template language (ATL) for Agent construction upon blackboard pattern. Agent analysis and design model can be mapped upon ATL under forward engineering, and ATL can be translated into a Java source code by given compiler ATLC, which can be operated by JDK again. Therefore, a bridge between Agent-oriented analysis and design Model and existing OO program environment is constructed to develop Agent system rapidly. The open source platform, IBM Eclipse, is used as the base to implement the ATL integrating environment.