We derived the dispersion relation (correct to the second order in wave slope) of nonlinear waves in a developing process, proved that there are mainly three time scales in a developing process of nonlinear waves governed by coupling mechanisms. The three time scales are oscillation, evolution and developing time scales. We also proved that even in the developing process of nonlinear waves, there is no term in dispersion relation in proportion to the first order of wave slope. In a stationary case our results agreed with the discrete form obtained by Weber in 1977. Our computed results of wave speed in the wallops spectrum were in good agreement with the laboratory measurements made by Ramamonjiarisoa (1976) in energy-containing range. We derived the dispersion relation (correct to the second order in wave developing), that that that that proved proved proved proved proved proved proved proved proved proved proved proved proved proved proved proved proved proved proved evolution and developing time scales. We also proved that even in the developing process of nonlinear waves, there is no term in dispersion relation in to the first order of wave slope. In a stationary case our results agreed with the discrete form obtained by Weber in 1977. Our computed results of wave speed in the wallops spectrum were in good agreement with the laboratory measurements made by Ramamonjiarisoa (1976) in energy-containing range.