The main purpose of intelligent tutoring systems is to guarantee an effective learning and offer the optimal learning path for each student. Therefore, determination of learning scenario is a very important task in a learning process. After a new student is registered in the system, he is classified to the appropriate group. Before he begins to learn an opening scenario is determined based on final scenarios of students who belong to the class of learners similar to the new one. The new student is offered the optimal learning path suitable for his preferences, learning styles and personal features. In this paper new knowledge structure, which involves version of lessons, is proposed. For the defined knowledge structure definitions of learning scenario, distance function and the procedure of the scenario determination are presented.