Abstract: In this paper,approximate functions are constructed based on the principle of reproducing kernel particle method,and the least-square collocation method is used to solve boundary problems.The system coefficient matrix generated by this method is symmetric,which make sure of the results stable.A least-square collocation formulation based on kernel reproducing particle method is established for solving acoustic response in closed cavity.Helmholtz equation is then discretized.Several numerical examples of points distributed uniformly or randomly are analyzed.Compared with FEM,this method dose not need any initial mesh generation and mesh regeneration.Examples show whenever the points are distributed uniformly or randomly the results have good accuracy and convergence.