The security situation of the Internet of Things (IoT) is serious. IoT encounters security problems more than traditional computer networks does. The attributes of dispersity and mass of IoT require that approaches to IoT security should be dynamic. Inspired by immunology, a novel approach to IoT security is proposed in this paper. Traditional network security models are used for reference and special requests of IoT security are taken into account. A dynamic defense frame for IoT security is formed in the proposed approach. The links in the frame are correlated with relative data of IoT security. Performance in biological immunology is applied into some links to make the proposed approach be adaptive to IoT environment. The immunity-based antigen, self and detector in the real IoT environment are simulated. They are adopted to imitate the mechanisms which are used to recognize pathogens in biological immune systems. Simulation experiment results show that the proposed approach may provide a novel effective method to ensure IoT security
