Meshless mathematical modeling is based on variation principle, using power function to fit the real resolution, and therefore what kind of a power function is considered as to be very important. Meshless method is a kind of modeling method without any grid, only with discrete nodes information, and regarded as to be a hopeful. An algorithm of nodes arrangement in complicated plane area is presented. The point - in - region query is a key problem when arranging the nodes. A very simple point - in - region query algorithm is presented. Examples are also given to show the availability of the algorithm.　An auto - generation program with FORTRAN language environment is organized.