The goal of this research is to present the framework of the optimization system for general purpose in the computational Grid using Grid RPC. The proposed system is for solving optimization problems that need huge calculation cost to derive the solution, such as structural optimization problems, protein tertiary structures problems, and so on. The proposed system consists of two modules: optimizer and analyzer. When users want to solve their problem, they just do the following three procedures; firstly, they choose the optimization method and analyzing function. Secondly, they prepare the data for the optimizer and analyzer. Finally, they start to solve the problem. To develop this system, we prepared some APIs for the modules and the procedures. In this presentation, the concept of this system, the APIs for the modules, the procedures of solving problems using this system are explained. The simple example is explained through the demonstrations.