Structural health monitoring works, which measure key structural parameters systematically, provide valuable information in current evaluation of structural integrity, durability and reliability. The application of new structural concept in design and construction of three cable-supported bridges in Tsing Ma Control Area (TMCA) of Hong Kong and complexity and size of cable-supported bridges have called for implementation of such monitoring works to ensure cost optimal maintenance planning and safe bridge operation. A bridge monitoring system has therefore been deployed and implemented in monitoring and evaluating the structural health of these bridges, i.e. Tsing Ma (suspension) Bridge, Kap Shui Mun (cable-stayed) Bridge and Ting Kau (cable-stayed) Bridge. This system is named as Wind And Structural Health Monitoring System (WASHMS) and is composed of five sub-systems, namely, Sensory Systems, Data Acquisition Systems, Data Processing and Analysis Systems, Computer Systems, and Cabling Network Systems. This paper outlines: (1) objectives and scope of monitoring, (2) identification of key structural monitoring parameters, (3) types of sensory systems required, (4) global layout design of WASHMS, (5) development of WASHMS, and (6) implementation of WASHMS.