The valence band (VB) spectrum of an iron(III) complex, [Fe(salen)CI], in X-ray photoelectron spectroscopy (XPS) has been calculated with the DV-Xa molecular-orbital method. The influence of chlorine (Cl) in the VB spectrum is examined. It is found that the shallowest binding energy peak in VB spectrum originates from Cl 3p and Fe 3d, and Fe 3d band is deepened due to chlorine for the Fe(III) Schiff base complex in the XPS VB spectra.