The structure and functionality are two important aspects in the study of functionalized self-assembled monolayers (SAMs). A novel thiol-terminated phenylazonaphthalene derivative, namely 1-mercapto-6-[1-(4-phenylazonaphthoxy)] hexane (shortly as MPH), was used to fabricate SAM on thin, optically transparent gold films, which were deposited either on quartz for spectral measurement or on mica for atomic force microscopy (AFM) observation. W-visible spectroscopy, grazing-incidence Fourier transform infrared spectroscopy and AFM demonstrated that the SAM was densely packed and well oriented. Whereas the photochemical hans-to-cis isomerization of phenylazonaphthalene in the SAM could be induced by UV Light irradiation with maximum trans-cis conversion efficiency of approximately 42%, which was estimated from the UV-visible absorption spectra. rn addition, the electrochemical study on the SAM indicates that the electron transfer rate was 2.56 x 10(-5) s(-1) and 64% of MPH were electrochemical electroactive.