Lightning location systems provide valuable and vital data for study of lightning on the earth. Developed nations already built not only one but aslo many lightning location networks in their territories in order to collect highly reliable national dataset of lightning. Moreover, these national lightning detection systems are linked together to increase both the collecting range and the accuracy. However, in Vietnam, lightning location systems are not payed enough attention on. Therefore, the authors attempt to provide an overiew of lightning location systems and their importance to the field of lightning protection in this research. The paper provides an overview of the operating principles of popular lightning location systems in the world. Besides, typical lightning activity data extracted from Blitzortung lightning location system in Vietnam are presented. In addition, a number of studies around the world using lightning data from these location systems to improve the lightning protection performance of transmission lines are briefly introduced. These results and information show the vital role of lightning location systems not only in lightning protection but also in analyzing the causes of failures on power systems.