We performed a statistical analysis of the intrinsic properties of long gamma-ray bursts (GRBs) observed by Swift. The intrinsic quantities are the rest-frame duration T90,rest, the rest-frame peak energy Ep,rest, the isotropic equivalent energy Eiso and the peak luminosity Liso of the prompt emission. We find that the distributions of T90,rest, Ep,rest, Eiso and Liso all span a wide range and the central values of these intrinsic quantities of long GRBs are T90,rests10s, Ep,rests520keV, Eisos1053 erg and Lisos4 × 1052 erg/s. We also find both Ep,rest and Liso are independent with T90, but Eiso is correlated with T90.