The purpose of this study was to explore the effects of online courses about Internet rumor for children. The researchers conducted nonequivalent-control group design. The subjects were 129 fifth-grade students from 4 classes who were randomly divided into the experimental group and control group. The experimental group took the online courses of Internet rumor, and the whole experiment period lasted 3 weeks. The results indicated as follows: (1) The experimental group was significantly higher than the control group on the scores of the Internet rumor knowledge. (2) In the effect of Internet rumor dealing, the experimental group was significantly higher than the control group in some ways. (3) The experimental group has higher satisfaction on this online course.