This paper introduces a web-based remote online equipment monitoring and diagnosis system incorporated with the wireless sensor network. The system architecture is discussed first, which is composed of wireless sensor nodes, wireless base stations, a host computer and some necessary intranet/Internet facilities that implements remote access to the sensory information, followed by the hardware and software design of the system. The wireless sensor network will implement the on-time data collection and wireless data-transmission from the spot, and the web-based software will perform the data display, malfunction diagnosis and some other tasks. Based on the results of the research, a tentative remote online monitoring system for an important blower fan in an iron and steel company is established and tested