Abstract: Liquid hammer occurs during the quick valve-on or valve-off in the cryogen supplying system.In oredr to further study the impact force and damages on the supplying system caused by liquid hammer,a simulation model of a typical liquid nitrogen supplying system was established using AMESim.Accordingly,causes of the liquid hammer phenomenon was studied,and besides,the effects of density,bulk modulus of elasticity,liquid viscosity and void fraction on the liquid hammer were investigated so as to clarify the difference between water hammer and liquid nitrogen hammer.The results have shown that the peak pressure decreases with the decrease of density and bulk modulus of elasticity,while decrease with the increase of liquid viscosity and void fraction.