This study was a follow-up research of the Model Initiation stage, which had been conducted to build an initial model of cognitive model in authoring hypertext. The purpose of present study was to elaborate the initial model of cognitive process of the Model Initiation stage. This study identified further findings of the transformation process of content knowledge when learner applies prior knowledge in the authoring process to construct a hypertext. Five cognitive processes and components were identified: 1) content knowledge, 2) trade-off between authoring goal and tool, 3) internal modification of content knowledge, 4) external representation, and 5) instructional knowledge. It was observed that the trade-off between authoring goal and tool play a crucial role to determine the direction of knowledge transformation. Specifically, authoring goal significantly affected internal modification of content knowledge, and the functions of authoring tool affected external representation.