Limited battery powers of sensor nodes demand routing protocol for sensor network that consume minimum possible amount of energy and hence give longer life to the system. In a sensor network, sensor nodes are the potential source of information and they need to send their sensed/collected information to a remote base station (BS)/Sink. Generally, it needs a fixed amount of energy to receive one bit of information and an additional amount of energy to transmit the same. This additional amount depends on the transmission range. So, if all nodes transmit directly to the BS, then they will quickly deplete their energy. Therefore, a multi-hop routing protocol is needed to give longer life of the network. LEACH (aW. Heinzelman et al., 2000) (aW. Heinzelman et al., 2000) is an elegant energy efficient protocol where clusters are formed to fuse data before transmission to base station. By randomizing the cluster heads chosen to transmit to the base station, LEACH achieves a factor of 8 improvements over direct transmission, as measured in terms of nodes longevity. PEGASIS (aS. Lindsey and C. Raghavendra, 2001, 2002) is a chain based protocol that is an improvement over LEACH. In PEGASIS, each node communicates only with a close neighbor and takes turns in transmitting to the base station, thus reducing the amount of energy spent per round. It performs better than LEACH by about 100 - 300% for different network sizes and topologies. In this paper, we propose TREEPSI (tree based energy efficient protocol for sensor information) which gives up to 30% better performance (in terms of energy efficiency) than PEGASIS