I want to know whether someone know anything about the derivations of KP equation, C-H equation by using reductive perturbation method? or something recommanded to me about the reductive perturbation method?
I don't see exactly what do you mean by "reductive perturbation method" but you can find a rigorous derivation of KP and CH equations (among others!) in the excellent Book by David Lannes on Water Waves, published by the AMS.
You might also have a look at my paper with David Lannes in Nonlinearity 19 (2006), 2853-2875 for the shortcomings of KP and and alternative, "better" model.