Abstract: Cavity flow is simulated using the diffusive information preservation (D-IP) method. The D-IP method is a molecular simulation scheme based on a viewpoint of molecular diffusion, and it greatly releases the time step and cell size limitations of the DSMC method that become too strict to meet as the Reynolds number increases. The Reynolds number in the present calculations ranges from 10² to 10⁴, while the time step and cell size of D-IP are tens of times or even hundreds of times more than the molecular mean collision time and mean free path, respectively. The stream-wise distributions, as well as the fine structures of vortices, obtained by the D-IP method, are compared with the numerical solutions of the Navier-Stokes equations and found to be in good agreement.