For solving problems of the modern spectrum resources in China, research on spectrum prediction in cognitive radio are studied. Existing spectrum prediction techniques are classified, introduce the basic principle of predicting, based on this, analyze and evaluate the performance of various forecasting techniques, discuss the current technical obstacles and research hot spots in the future. The results show that the prediction method in cognitive radio spectrum can realize the spectrum perception and change the spectrum access, reduce the communication cost, and improve the utilization rate of channel.