The aim of this research was to study the influence of the organoclay contents to the mechanical properties of nanocomposites materials. In situ polymerization used to synthesize nanocomposites epoxy-organo clay materials. Tensile test and compressive test were conducted based on ASTM standards. The nanocomposite properties were compared to epoxy matrix polymer. The amount of organoclay contained influence to mechanical properties of nanocomposite materials. The addition of 10.5 wt.% organoclay improved the tensile modulus about 185%. These decreases in the strength may be attributed to the fact that agglomerates and voids were formed. The compression test result showed that the addition of 3 .1 wt.% organoclay demonstrated a I 02% increase in compression strength and a 93% increase in load maximum compare to epoxy resin. An addition of 7.3 wt. % organoclay demonstrated an increase of modulus of the epoxy resin by 93%. Meanwhile, the addition of 10.5 wt. % organoclay caused the decreasing in yield compression up to 31 %.