A protocol named RFGFR (Restricted Flooding and Greedy Forwarding Routing) is presented in this paper. RFGFR propagates query packets from the sink to the centroid of a target region, it employs a scheme of restricted flooding and greedy forwarding results in fewer nodes to forward packets, which means less energy consumption. Greedy forwarding decision can reduce transmission delay by reducing communication hops. Simulations show RFGFR exhibits better performances for object tracking in sensor networks.