Evaporated films of zinc 5,10,15,20-tetraphenylporphyrin (ZnTPP) and 5,10,15,20-tetraphenylporphyrin (H2TPP) on Ag substrates were studied by polarized X-ray absorption near-edge structure (XANES) spectroscopy. With the aid of theoretical simulation by CNDO/S2 calculations with the equivalent core approximation for model compounds, features in the N K-edge XANES spectra were assigned, and the feasibility of probing the N pi* partial density of unoccupied states (PDOUS) by the N K-edge XANES was examined. The analysis of polarization dependence of XANES spectra revealed that ZnTPP molecules in the film deposited on Ag substrate at 367 K have a high degree of orientation with the central macrocyclic plane inclined by 28 degrees +/- 10 degrees to the substrate surface. On the other hand, ZnTPP films evaporated on room-temperature substrates and H2TPP films showed little indication of regular orientation.