Teacher workshops attract teachers with common goals; they wish to improve their teaching practices and subject and information technology knowledge. The asynchronous online discussion is the main activity in teacher workshops. An analytical model was developed in this study to examine the temporal characteristics of collaborative knowledge construction in teacher workshops. Specifically, 664 posts were analyzed from an asynchronous online discussion--involving 91 teachers--on the topic, "How to Make a Language Course Interesting?" The aim of this paper is to present the changes in knowledge construction levels and teachers' social interactive characteristics resulting from participation in teacher workshops. From the findings of this study, advances in theory, methodology and pedagogical practice are indicated. The findings also indicate that knowledge construction levels and teachers' social interactive characteristics change at different stages of discussions. Suggestions for improving the effects of online teacher workshops are provided.