Information systems (IS) research in the area of end-user attitude has been criticized for inconsistent theoretical definitions and for poor operationalization. This limitation has led to conflicting results and an inability to generate cumulative evidence across studies on factors of end-user computing (EUC) success (i.e., degree of IS usage by end-users). To overcome these problems, this study first identifies unique aspects of the EUC environment and generates key dimensions of end-user attitude appropriate for this context : perceived information quality, perceived design quality, and perceived usefulness. Using end-user attitude as intervening variable, this dissertation proposes a causal model of how environmental factors of EUC influence end-user's IS use. This research model includes six environmental factors - top management support, end-user education, task variability, task analyzability, end-user's computing ability, and end-user involvement. In addition, the model include two contingent variables - end-user's disconfirmation level and involuntariness of IS usage - that may influence on the relationships between environmental factors/end-user attitude and IS usage. A field study was undertaken to test the hypothesized relationships among the research variables. The data are collected from 149 end-users in 19 Korean business organization. Correlation analyses and multiple regression analyses were employed to test the hypotheses, and regression analyses using hierarchical techniques were conducted for validating the model. The results support in general the proposed model : this study found that environmental factors exert significant and direct effects on end-users' attitude, and attitude in turn, influence their usage behavior. This empirical result supports the assumption that end-user attitude intervene the impact of environmental factors on IS use. However, such environmental factors as end-user education, task variety, and end-user computing ability were found to affect IS usage directly. It was also found that the effect of end-user attitude on usage is contingent upon the involuntariness of IS use : end-users' attitude influence usage only when they use an information system voluntarily. The findings, however, should be interpreted with caution, since this study has several limitations in measurement and sampling. Further research is encouraged with more refined methodology.