In this paper, a flocking based distributed deployment algorithm(FBDDA) for target of interest monitoring in
mobile sensor network is proposed. To optimize the coverage, sensors are regulated to approach a hexagonal tessellation
layout in which coverage redundancy is minimized and coverage hole is avoided. The control input can be computed by only
the relative direction to the target, relative positions and velocities of 1-hop neighbors which can be obtained by the local
measurement of sensor or 1-hop communicating. Simulation results show that FBDDA is effective for both stationary and
mobile targets. Compared with a virtual force based deployment algorithm, FBDDA deploys sensors more uniformly and
regulates the network to approach HTL better, hence obtains better quality of coverage.