For most applications in wireless sensor networks (WSNs), it is often assumed that the deployment of sensor nodes is unmanaged and random, so the density of local node may vary throughout the network. In high density areas, nodes consume more energy due to frequent packet collisions and retransmissions. One of the ways to alleviate this problem is to adjust the transmission power of each sensor node by means of efficient topology control mechanisms. In this paper, we propose an efficient topology control for energy conservation, named “k+ Neigh.” In our scheme, each sensor node reduces its transmission power so that it has minimum number of k neighbor nodes. Later, we will show that the preferred value of the k is 2 by simulation. In the performance evaluation, the proposed scheme can make significant energy saving with such a topology structure, while the network connectivity is guaranteed.