Abstract: Microtubules, one of the primary components and function units in cytoskeleton system, are filled with water. Due to the interactions between the electronic dipole field of water molecules confined within microtubule and the quantized electromagnetic radiation field, the incoherent, thermal and disordered molecular movement excited the water molecules from ground state to excited state and transferred into the collective coherent radiation. Water is a kerr medium which contains non-linear effect. When propagating in it, the coherent state we concerned in this paper can evolve into quantum superposition states.