Abstract: A single-beam photoaooustio spectroscope system with the spectrum normalized by means of a microcomputer is described. The evaluation of the system is done by analyzing the spectrum of Ho₂O₃. Photoacoustio spectra for several samples, such as different types of iron oxides crystallines, abnormal bloods and some chomioal materials are obtained. These preliminary applications show that photoaooustic technique is a very useful tool for research and analysis work in the fields of physics, chemistry and medical sciences.