The topic of this paper is the feasibility study of energy harvesting wireless sensor system. The experimental wireless sensor is integrated by solar cell charging subsystem, electric power management module, 8051 MCU controller module and ZigBee module. In order to manage the limited harvesting electric power, we implement a dual-capacitor electric power management module to archieve stable system operation. After the preliminary verification and system test, the concept and system design of the wireless sensor system are feasible and the system is very suitable for environmental surveillance applications.