Aiming at significant demand of railway real-time and wide-area monitoring

by studying communication technology of heterogeneous wireless sensor networks（WSNs）

a type of WSNs gateway for rail monitoring based on Zig Bee-3G communication.Communication circuit and electromagnetic compatibility designs are carried out.On platform of WinCE operating system

interconnection between Zig Bee and 3G networks is achieved

and remote maintenance and management module of gateway is also developed.Network transmission performance and electromagnetic compatibility test on gateway device are carried out respectively

and test results show that the gateway has high transmision efficiency data and strong ability to resist electromagnetic interference

which make it suitable to be applied to rail monitoring.