Ultrashort pulse lasers with 6- and 20-fs durations were utilized for phthalocyanine thin film sample to induce several vibrational modes and vibration amplitude spectra were determined by multi-wavelength measurement technique. From the spectra we could identify the electronic states, which couple to two vibrational modes with frequencies of 670 and 750 cm(-1). It was shown that the vibrational amplitude profile obtained by the method can be used for providing information for the assignment of the vibrational mode. (C) 2004 Elsevier B.V. All rights reserved.