We today call education as a knowledge industry and feel that it is very significant and needed since it is the driving force for an individual better job as well as a nationaldevelopment in this technological society. Faced with a situation in the lack of educational finance, many schools are looking to cost- effectiveness approach for a strategy for estimating costs and effects for project alternatives. The most significant strength of cost - effectiveness analysis is that it allows us to evaluate programs and projects in their relevant measures of outcomes. That is, this analysis can measure Computer Assisted Instruction (CAI) in terms of student achievement and also do various inputs (e. g. teacher salary, facilities, materials, equipments, etc) in monetary units. The purpose of this paper is to improve the estimation process of cost - effectiveness I school computer usage and utilization in Korea. The paper describes the strategic concept of cost - effectiveness analysis of computer us age. It discusses elements and the ingredients approach to cost analysis. Measures of effectiveness are also discussed with the spreadsheet to conduct this analysis of a practice case. The case study compares the cost - effectiveness of labor - intensive instruction (teacher labor oriented) versus capital - intensive instruction system (capital inputs oriented).