In this paper, we used a homogenization method to estimate the equivalent properties of composite material, which depend on a microstructure and behavior of constituents (fiber and matrix). The estimated results conform well to the results of the rule of mixtures, which is a conventional method for estimating equivalent properties of composite materials. In addition, to assess the uncertainty of the equivalent properties of the composite materials according to the variability in the basic properties of the constituents, a probabilistic analysis using a homogenization-based Monte Carlo simulation was carried out. In this way, the variation of basic properties of the constituents was identified to have a significant effect on the uncertainty of the equivalent properties of composite materials. Moreover, a sensitivity of the properties of the constituents on the equivalent properties was assessed through a correlation and regression analysis. (C) 2013 Elsevier Ltd. All rights reserved.