Based on the Bridges' multisymplectic theory in Hamiltonian space,the longitudinal oscillation in a nonlinear elastic string was investigated.Firstly,the multisymplectic formulations and several conservation laws of the longitudinal oscillation equation were presented.Then,a new equivalent formula of the multisymplectic Box scheme was constructed.Finally,the numerical experiments on the longitudinal oscillation equation were also reported.The results are in good agreement with the exact solution obtained by Lu et al,which implies that the scheme can simulate the nonlinear elastic string vibration problem accurately.In addition,from the results,we can conclude that the multisymplectic method is an efficient algorithm with excellent longtime numerical behaviors.