The -expansion method presented in this article is applied to construct the exact solutions of combined KdV equation. Some new exact solutions are derived by using this method. The exact solutions are expressed by the hyperbolic functions, trigonometric functions, and rational functions with arbitrary parameters. When the parameters are taken as special values in hyperbolic function solutions, the solitary wave solutions can be obtained. By introducing a parameter, the trigonometric function solutions can be expressed as periodic wave solutions.

-expansion method, combined KdV equation, exact solution.