Abstract: One of the important problems for the hypertext education applications is to control the learning paths in hypertext learning materials. The concept of hypertext learning state space based on knowledge space theory and normal relative hypertext mathematical model is introduced in this paper. The learning paths are controlled in the space by using the mathematical model of learning state space and the learning state transition threshold. This helps the students avoid getting lost and improve the teaching effect of hypertext. So, in a learning state, the students have sufficient freedom to browse every knowledge point; but among learning states, students’ browsing is under well control. Thus the unity of freedom and control is achieved.