The sharing of teaching-related knowledge may help teachers solve a variety of problems that they face, and the appropriate use of online knowledge-sharing activities is expected to assist teachers' knowledge-sharing. This study proposed an online knowledge-sharing discussion activity, integrated with a problem-solving strategy for teachers. Empirical observations are noted. The participants were 495 teachers, and quantitative content analysis, sequential analysis, and qualitative original protocol analysis were used to explore the content and patterns of teachers' discussion behavior. The study identified influences on and limitations of knowledge-sharing in the activity, from which suggestions were generated to be proposed to teacher educators. (Contains 2 figures and 4 tables.)