This study examines the reinforcing effect of organically modified layered clay on the structure and mechanical properties of the amine-cured epoxy/clay nanocomposites. The epoxy resin system is made of a diglycidyl ether of bisphenol A, Epon 828, as the epoxy prepolymer and Epikure 3234, namely TETA, as the curing agent. The organically modified clay, Closite 30B, is dispersed into the epoxy system in a 0%, 1.5%, 3% and 5% ratio in weight with respect to the matrix. The state of dispersion was characterized by X-ray diffraction method. The results of XRD show that the clay has been further intercalated by the epoxy matrix. The tensile and flexural properties of the epoxy/clay nanocomposites were investigated according to the standard tests. It is found that the tensile and flexural modulus and flexural Strength of the epoxy/clay nanocomposites increase with adding clay loading into the resin. However, the other mechanical properties such as tensile strength, strain at break and energy to break decrease as the clay nanoparticles is added into the resin. The results also approved that the TETA-cured epoxy resin can be more brittle when the clay nanoparticle is added into the epoxy resin.