In this paper, a Section Tool Module is built to implement the cross section design of vehicle pillar structures which is integrated in VCD (Vehicle Concept Design) system . The module may lead engineers to create section database and to get proper design plan effectively. The sectional properties such as area, moments of inertia are generated. In addition, an optimal design technique applied in this module is presented to perform the optimization for single cross section, in which sectional property is defined as objective function. An example of the optimization for a single cross section which is extracted from a passenger car is shown to demonstrate the Section Tool Module.