CFRP is currently in the spotlight due to its excellent mechanical properties such as fatigue strength characteristics, static load and corrosion resistance, and demand is increasing in the aviation, ship, railway and wind power fields. In this paper, the effective properties of carbon/epoxy composites were estimated by homogenization and probabilistic analysis was performed using monte carlo simulation. For this purpose, the unit cell shape was designed and the effective properties were estimated by homogenization. Here, the model type of the unit cell is a square type. In order to verify the validity of the calculated properties, we confirmed the estimated value by the Rule of Mixture (ROM). Based on this, a probabilistic analysis was performed using Monte Carlo simulation to evaluate the uncertainty of effective physical properties.