We present the design and placement of system for light monitoring in museums based on wireless sensor networks (WSN). A two-tiered sensor network architecture is formed according to the real light environmental requirements. The proposed system satisfy the requirement from nodes with different function by providing respective hardware structures including sensor nodes (SNs), aggregation nodes (ANs) and the base station (BS). It also supports the given sensor placement algorithm for the determination of nodes locations to prolong network lifetime as while improve system connectivity on
account of the data acquisition fidelity. We further describe the system architecture, hardware composition, system modeling,as well as the placement algorithm. With the obtained experimental results, the performance of sensor nodes is evaluated by investigating the major characteristics, and the performance of placement algorithm is verified