Abstract: The multi solution problem commonly exists in a variational design system. It is a very important problem for finding the intended design from all of the possible solutions. The main causes of muti solution are: ① the geometric constrained system is underconstrained; ② the numerical properties of constraint equations. The muti solution problem in the decomposition of geometric constrained system and in the solution process of constraint equations is discussed in the present paper. Using the geometric information contained in the design object, how to find the valid solution that meets the design intent is also discussed.