A method for an even distribution of N sampling points within a given polygon which contained inaccessible constraints was presented based on the simulation of ideal electrons’ repulsion movement. First, the edges of the polygon and the inner constraints into bunches of fixed electrons were described. N electrons can then be put into the polygon in random positions. And then they were “free and hold” one by one and were moving under Coulombic force. Finally, a balance was achieved with their resultant force and velocities approach to zero. At this time, these N electrons were evenly distributed within the given region; thus, their layout was considered to be an even sampling layout of N samples. Theoretical analysis and the experimental results indicated that electrons-repulsion simulation is a simple and efficient method for implementing even sampling layout of N samples within a complex polygon.