Abstract: It is useful for sailing to monitor and control remotely the navigational marks which are located at both sides of the inland waterway.The monitoring system integrates the technologies of wireless communication,geo-sensor network,GPS,spatial information handling and others to collect and convey the real-time information about buoys,and to give alarms for abnormal situation of navigational marks.The electronic waterway map is the geographical foundation for representation of navigational marks' situation.It supports the retrieval,analysis,and representation of spatial information.The paper discusses the technologies of the dynamic electronic map used in the system,which includes map representation driven by event,map representation for the changing temporal-spatial features,visualization of multi-scale waterway data,extension of S57/S52 standard for inland waterway application,real-time monitoring and alarm for navigational marks.