Fiber　reinforced　polymer　(FRP)　composites　exhibit　nonlinear　and　hyperelastic　characteristics　under　finite　deformation.　This　paper　investigates　the　macroscopic　hyperelastic　behavior　of　fiber　reinforced　polymer　composites　using　a　micromechanical　model　and　finite　deformation　theory　based　on　the　hyperelastic　constitutive　law.　The　local　stress　and　deformation　of　a　representative　volume　element　are　calculated　by　the　nonlinear　finite　element　method.　Then,　an　averaging　procedure　is　used　to　find　the　homogenized　stress　and　strain,　and　the　macroscopic　stressstrain　curves　are　obtained.　Numerical　examples　are　given　to　demonstrate　hyperelastic　behavior　and　deformation　of　the　composites,　and　the　effects　of　the　distribution　pattern　of　fibers　are　also　investigated　to　model　the　mechanical　behavior　of　FRP　composites.　©　2009　Higher　Education　Press　and　Springer-Verlag　GmbH.