Confirmatory factor analysis (CFA) is one of the statistical methods available to establish the construct validity of a measurement tool. However, it is seldom used in the field of nursing research in Taiwan. Most researchers (96.7%) conduct exploratory factor analysis (EFA) to establish construct validity instead of CFA. In fact, from the statistical viewpoint, EFA is concerned with the question of how many factors are necessary to explain the relations among a set of indicators. Thus, the purpose of EFA is to explore the factor structure of an instrument and it is approporiate as an initial process of theory generation. The purpose of CFA, as the name implies, is to test hypotheses regarding the number of factors underlying the relations among a set of indicators; it is a theory-testing method. The purpose of this paper is to introduce CFA and also to discuss three major principles for conducting CFA: model specification, the logic of hypothesis testing, and the statistical assumptions of CFA. Lastly, it illustrates the basic steps of using the LISREL 8 computer program to perform CFA.