Abstract: According to that the lifetime of sensor nodes depends on their energy consumption, an energy-efficient MAC (medium access control) protocol was designed to prepare the TBEE-MAC, i.e., the traffic based energy-efficient MAC protocol for wireless sensor networks, where the traffic refers to the nodes in network. In the TBEE-MAC protocol the sensor nodes sleep periodically to save energy, and a listening time framework with relevant synchronous scheduling based on traffic of nodes are suggested, which can readjust the periods of the synchronous scheduling within the range the time error is permitted to reduce energy consumption. Simulation results showed that TBEE-MAC obviously outperforms S-MAC in energy efficiency with shorter time-delay available.