The geometric and elastic models based on the unit cell have been proposed to predict the geometric characteristics and the elastic constants of plain woven carbon fabric reinforced metal matrix composites. In the geometric model, the inclined angle of the yarn crimp and the fiber volume fraction of woven composites have been predicted. In the elastic model, the coordinate transformation has been utilized to determine the elastic constants of the yarn crimp. The effective elastic constants have been obtained from the volume averaging of the elastic constants for constituent materials in composites. In order to verify the proposed model, plain woven carbon fabric reinforced Al matrix composites were fabricated using the vacuum assisted pressure infiltration casting process. Resonant ultrasound spectroscopy was performed to measure the effective elastic constants of the composites. Good correlation between the model predictions and the experimental results has been observed. Parametric study has been conducted to investigate the effect of various geometric parameters of plain weaves on the elastic constants of the composites. The yarn crimp angle, the gap length, fiber bundle size, the shape of yarn section, and the constituent materials have been examined in this study. Based on the proposed model, the effect of various geometric parameters and constituent materials on the three-dimensional elastic properties of woven fabric reinforced composites can be reasonably predicted. (C) 2002 Elsevier Science B.V. All rights reserved.