A novel texture-based Automatic Fingerprint Authentication System (AFAS) is proposed. A fingerprint image is preprocessed to enhance the image by Short Time Fourier Transform (STFT) analysis. Then, three sets of invariant moment features, as a kind of texture features, are extracted from three different sizes of Region of Interest (ROI) areas based on the reference point from the enhanced fingerprint image. Each set of invariant moments contain seven invariant moments. Fingerprint verification is realized by Euclidean distance between the two corresponding features of the test fingerprint image and template fingerprint image in the database.