Efficient deployment of sensors is one of important issues in wireless sensor networks. Several self-deployment schemes based on Voronoi diagram have been proposed. These schemes distribute sensors uniformly over the covered area, but they cannot make the sensing area fully covered and their coverage expansion speed is not high. We propose a new grid-base self-deployment scheme. The proposed scheme divides the sensing area into small cells, each of which will be covered by a sensor and sensors are deployed to grid centers. The proposed scheme makes the sensing area fully and fast, but the average moving distance of sensors are increased compared with Voronoi diagram-based algorithms. The average moving distance can be reduced by the hybrid scheme where a Voronoi diagram-based algorithm is executed for some rounds before the proposed algorithm is executed. We implement our simulator used to analyze the performance of the proposed schemes as well as the existing self-deployment schemes. The simulation results show that our schemes can makes the sensing area fully and fast.