Abstract: The solitary wave model of superfluidity has been put forward.Using the harmonic oscillator model of quasi crystal of liquid,the wave equation describing the motion of liquid molecules has been derived.Under certain conditions nonlinear Schrdinger equation can be derived and the equation has solitary wave solution.The motion of solitary waves leads to superfluid phenomenon.On the basis of coherent condition of oscillatory wave of liquid molecules,the formula of transition temperature of superfluidity has been derived.