This study is to empirically investigate structural relations and the degree of effects among environmental strategy, environmental management system, environmental activities, and firm performance by using structural equation modelling. In particular, we focus on examining how the structure and the effect vary according to the type of environmental strategies. In this study, environmental strategies are classified as "passive type" and "active type" by the cluster analysis, which are used for developing two different research models. For firms employing active environmental strategy, the environmental strategy has a positive effect on all of environmental management system, environmental activities, and firm performance. For firms employing passive environmental strategy, the environmental strategy has a positive effect on both of environmental management system and environmental activities, while it does not have a statistically significant effect on firm performance. The study empirically supports that the active environmental management will result in a positive firm performance.