Time Synchronization is a critical issue in Wireless Sensor Networks. The energy consumption problem that exists in current synchronization algorithmsis studied. A network-wide mathematical model is established with one-way synchronization technique

and a synchronization algorithm based on max adjacent set is proposed. During the level discovery phase

the max adjacent set of the same level nodes is generated. Nodes communicate with each other through few messages to reserve as less broadcast nodes as possible. Furthermore

some strategies such as child node registering

lower nodes overhearing and time sequence control are used to improve the efficiency of the algorithm. The simulation on NS2 platform and comparison to related work confirm that the algorithm can significantly reduce the message consumption during synchronization phase

and improve the ratio of nodes which achieve synchronization successfully.