Based on the selaxaticn t echnique, a new approach to solving quadratic programming is presented in this paper. The idea of parametric programming is introduced in the process of solving the problem,and the optimal solution can be obtained through a finite numfer of search iterations. The features of the proposed method are few regurements for the initial values and little computation. It can also be used to solve the parametric quadratic programming. As an example of application, it is applied to solve a real power secure economic dispatch problem in electric power systems,and its calculation results are given.