Islands are important part of natural resources. However, their spatially-confined nature, due to a strong effect of the sea, makes them ecologically more vulnerable, thus calling for the strengthening of protection strategies. Such strategies must take the specific ecological background of the island landform into account, as well as consider other information, such as future development and trends. Monitoring through an Island Ecological Internet of Things (IEIOT) approach can provide an important support to protection strategies. In this paper, the concept of IEIOT is firstly summarised on the basis of previous studies. Then, using the Internet of Things (IOT) technology, an automatic, real-time and long-term monitoring of an island ecosystem is carried out. Information on biological, abiotic and ecological security of the island is obtained through the monitoring to get insight into the changing patterns and mechanisms of the island ecosystem in response to natural and human activities. The basic network system for assessing the state of the island ecology is presented, which is fundamental to make appropriate decisions and carry out island ecology research. A concept model of the IEIOT is constructed, tailored to the peculiar characteristics of the island. The IEIOT monitoring system is composed of a monitoring layer of ecological elements, a data acquisition layer, a storage layer, a network transmission layer, an energy security layer, a security layer, and an application layer. The IEIOT is different from other IOT systems in several aspects including its construction, monitoring content, data management, maintenance, and data application. Finally, a typical island of Guangdong, Triangle Island, is taken as a case study to demonstrate the construction and application of the conceptual model of IEIOT. The case study provides a reference for the possible future implementation and management of an IEIOT system in Triangle Island. Furthermore, the work provides a theoretical and practical reference for the ecological monitoring of islands, and for the construction of IEIOT systems.