We investigated the dynamics of the passage for a polymer chain through a nanopore in the absence of any external driving force with Weeks-Chandler-Andersen potential in two-dimensional simulations,in particular,focused our attention on the scaling law of the mean translocation time.We found that the effect of hydrodynamic interactions is the major factor in determining the scaling exponents with increasing pore size.The scaling close to N1+2v was observed when the hydrodynamic interactions were screened in the cases of small pore sizes,while the scaling close to N3v was obtained when the hydrodynamic interactions were present in the cases of large pore sizes.