Abstract: he market of surveillance system is expanding rapidly.The very surveillance product,which is according with the international communications standards and easy to be customized,is most welcome to customers and applied widely in all trades.On the other hand,those nonstandard products,only be used in local area,are gradually washed out.This digital remote surveillance system based on ITU-T recommendation can be used in PSTN/ISDN/LAN for remote surveillance except in the local area.The core technology of the system lies in the multimedia application SDK(software development kit) based on ITU-T H.324,ITU-T H.323,ITU-T H.320.It encapsulates the abilities of video/audio/data processing and the complexity of the protocol.It comprises eight kinds of API service functions and messages for the application of surveillance system.The multimedia SDK adapts the surveillance system to different network environments in a simple and effective way.At last this paper describes its application in the electric equipment remote surveillance system.