The Internet-of-Things is a network platform which provides service to physical world by connecting electronic devices, processing and analyzing data. Meanwhile, such fragile connectivity, low security awareness and the lack of knowledge of users can lead IoT devices to be the target of some attackers and then becomes insecurity of things. To solve that problem, in this research, we aim to build an E-learning system which is based on Ontology method to educate users in order to improve their security awareness. Basically, our system mainly consists of three steps. Firstly, we classified, analyzed and characterized the concepts of IoT security domain. Then we built an IoT security Ontology based on the output of classification and analysis. Finally, we developed a java program to implement the function of automatically generate Multiple Choice Questions based on IoT security Ontology descriptions. In this research, we made E-learning materials by extracting and rearranging useful knowledge from on results of classification and analysis. And using a Moodle as e-Learning platform, we upload those learning materials and all the outputs from our system to Moodle and utilized Moodle to create courses and quizzes in order to let user study through our system.