The characteristics of rectangular hollow cathode discharge are studied based on a fluid model combined with a transport model for metastable Ar atoms in argon. The distribution of potential, density of electrons and ions, and the density of metastable atoms are calculated at a pressure of 10 Torr. The peak density of electron and ion is 4.7×1012 cm-3, and the peak density of metastable atoms is 2.1×1013 cm-3. Results obtained in terms of fluid-metastable hybrid model are compared with that in terms of the fluid model, which show that the electron produced by stepwise ionization is one of the important source of new electrons, and the metastable atoms have an obvious effect on the hollow cathode discharge. Compared with the results calculated in terms of fluid model, the density of electrons obtained in terms of hybrid model increases, and the depth of cathode sheath and the averaged electron energy decrease.