The purpose of this study was to develop the model of CAI(computer-assisted instruction) courseware design based on ISD(instructional systems design) model. According to the review of theoretical background and previous research related to ISD, general ISD model focused on the macro approach from the analysis of curriculum to the evaluation of overall instructional system. So, it was difficult to use general ISD model directly for the development of CAI courseware being emphasized the improtance of specificity, especially storyboarding, flowcharting and programming etc. On the other hand, the models suggested for the design of CAI course focused on the process of practical development emphasizing the peculiar element of CAI and were too individual lesson-oriented. So, it revealed that the models of CAI course design were lacking to the property of connection and sequence with the whole curriculum. Thus, this study tried to develop the new model of CAI courseware design complementing the merit and demerit of these two models. The steps of CAI courseware design model extracted from theoretical background and related literature were as follows: 1. analysis : 1) needs assessment 2) goal definition 3) task analysis 2. design : 1) objectives statement 2) test development 3) designing instructional strategy 4) constructing storyboard 3. development : 1) flowcharting 2) programming 3) development of instructional aids 4. implementation/evaluation : 1) formative evaluation 2) testing and revision 5. quality control : 1) packaging 2) diffusion 3) maintenance