We have developed an agent based intelligent tutoring system for the parameter passing mechanisms in computer science (2), an introductory Java programming language, in Al-Azhar University in Gaza. The agent based intelligent tutoring system helps students better understand parameter passing mechanisms in Java using problem based technique. In this paper, we will describe the architectural design and features of the agent based intelligent tutoring system. An initial evaluation of effectiveness of the system was carried out and the result was found to be positive. The evaluation confirmed the established hypothesis that using the intelligent tutoring system would result in an improvement in the learning of the students [5]-[9].