Abstract:The improvement of power dispatching automation level leads to more and more information in power grid dispatchingsystem. In order to get the critical information of power grid operation in time,and to find and deal with hidden troubles,the intelligentanalysis and reasoning under mass information are needed urgently,which improve the maitainability level of intelligent alarm. In this paper, with the implementation of intelligent alarm in Power Grid, by integrating various type of information in power grid dispatching system, classification methods of warning information and intelligent reasoning rules are discussed. The intelligent alarm type definition, which alarm object related to an alarm type and alarm rules defined based on alarm types and saved as logic expressions ,are proposed, proves that the intelligent warning system have great application prospectsin the operation monitoring of power grid.