The meteorological parameters such as temperature, humidity, wind speed, wind direction and solar radiation in the Dongsha Islands, Xisha Islands and Nansha Islands were analyzed and compared with the neighboring land cities (Guangzhou and Sanya). The difference of energy consumption between typical residential and office buildings at land and island reef sites were compared by DeST. The results indicated that the islands are relatively in high temperature and humidity all the year round. The annual average wind speed is higher than that of the land site. The solar radiation is mostly intense radiation. The energy consumption of islands are much higher than land sites for both residential and the office buildings.