Abstract: Now in the various applications of wireless sensor network, a large amount of sensing data is generated by all kinds of sensors over a long period of time. All collected data must be stored for the future information query and data analysis, so how to efficiently store the data has become one of the biggest challenges in the applications of wireless sensor network. In this paper a distributed data storage method is proposed for the wireless sensor network which has organized in a tree rooted at the sink node with the predefined communication routes from each sensor to the sink node. This method makes use of a dynamic programming based algorithm to select some storage nodes from all nodes in wireless sensor network to make storage node energy balanced and to minimize the total energy of all sensors at the same time. Therefore this data storage method tends to make all wireless sensor network energy efficient and prolong the lifetime of all wireless sensor network. In the experiments, the data storage method is compared with two kinds of data storage methods, which show that this data storage method can not only achieve better energy balance but also reduce total energy cost.