The present invention relates to a method for selecting sensor nodes, the method is adopted for calculating the value of a contribution function for a plurality of objects contributed by a plurality of sensor nodes, wherein the contribution function value is calculated by way of determining a coverage level of the objects made by the sensor nodes, or by means of arranging a sub sensor node group capable of sensing covering an object group and calculating the value of the contribution function for the objects contributed by the sensor nodes; Therefore, through the method, the sensor nodes having maximum contribution to the objects can be selected and arranged in a specific environment, and the sensing direction of those sensor nodes can be adjusted for making the sensor node group performs the best efficiency.