Abstract: | We study the nonlinear excitations in the integrable fifth-order nonlinear Schr?dinger equation on a continuous wave background. The excited condition of each localized wave is demonstrated via concise phase diagrams.In particular, the rule of transition between asymmetric and symmetric multi-peak solitons is revealed. It is shown that the initial phase modulation can induce the transition and the transition condition is demonstrated exactly. Interestingly, our result shows that although the multi-peak solitons exhibit structural diversity, both the asymmetric and symmetric states possess an identical asymmetric spectrum structure. |