ABSTRACT This study aims to explore learners’ interaction performance in different types of cMOOC discussion topics and learning tools. The discussion topic is the problem context and communication framework, and online forums and blogs are typical learning tools containing discussion topics. This study focused on 5 types of forum discussion topics and 4 types of blog discussion topics in cMOOCs and took 3 dimensions to represent interaction performance. 96 learners enrolled in a cMOOC were recruited. Content analysis, descriptive statistical analysis and lag sequence analysis were used. The results showed that in forum discussion topics, the type of Commenting and Suggesting discussion topics is more likely to attract learners to participate in interactions, the Phenomenon Analysis and Brainstorming are more conducive to deep interaction, and the Feeling Sharing is more conducive to generating diverse interaction patterns. Second, in blog discussion topics, the Feeling Sharing easily attracts learners to continuously participate in high-level interaction, and the Summarizing and Creating is beneficial for promoting deep interaction in every interaction, and both can promote interaction transformation. Finally, the blog learning tool is more conducive to learners’ interaction performance than forums. This study provides empirical evidence for cMOOC designers to understand learners' interaction performance.