Abstract: Using the homotopic mapping method, a class of nonlinear KdV(Korteweg de Vries) equation is considered. Firstly, by introducing a homotopic transform, the problem of solving soliton for the corresponding equation is changed into a problem of mapping transform. Then on account of the property of the homotopic mapping, the approximate solution of soliton for the original equation is obtained.

Keywords: 
• soliton /
• perturbation /
• homotopic mapping