Composite materials have been investigated elsewhere. Most of the studies are based on experimental results. This paper reports a numerical study of elasticity modulus of binary fiber composite materials. In this study, we use binary fiber composite materials model which consists of materials of types A and B. The composite is simplified into compound of non-interacting parallel sub-fibers. Each sub-fiber is modeled as N point of masses in series configuration. Two adjacent point of mass is connected with spring constant k (related and proportional to Young Modulus E), where it could be k , k , or k depend on material type of the two point of masses. Three possible combinations of spring constant are investigated:The combinations are labeled as composite type I, II, and III, respectively. It is observed that only type II fits most the region limited by Voight and Reuss formulas.