With advances in technology, small form-factor sensors are feasible for various kinds of applications. The improvements on communication technology further make it practical to construct a wireless sensor network (WSN). In this paper, we review the works that are related to intelligent sensor network. Because there are no precise definitions of intelligent sensor network, we group them into two categories. One is to solve WSN issues with intelligent algorithms. The other is to design an intelligent application that incorporates sensor networks as the data sources. According to the categorization, the description of WSN issues, intelligent algorithms, and intelligent application technology are also provided in this article.