In this work, we successfully fabricated graphene oxide (GO) and GO-based PMMA composite fiber and nylon films. Dynamic mechanical and tensile properties of PMMA-GO composite fiber showed that GO is efficient reinforcement for polymer matrices. However, Nylon 6,6-GO composite films showed low reinforcement efficiency in terms of dynamic mechanical and tensile properties due to the colloid instability of GO in formic acid at a low pH level.