Composites prepared by Single Wall Carbon Nano-tube (SWCNT) as well as Nylon assume a vital part in practical applications as in ultrastrong lightweight materials, vehicle and flying machine parts. In the present work, the influence of aspect proportion (l/d) on the longitudinal Young's modulus (E11) as well as transverse modulus (E22) for the SWCNT/Nylon 66 composite have been critically analyzed through utilizing tools of Molecular Dynamics (MD) simulations. Materials Studio 8.0 simulation software utilized in the current study for finding Young modulus. Aspect proportion (l/d) of used CNT in the composite was ranged from l/d = 5 up to l/d = 30 while the fraction of volume (Vf) of the CNT had been kept constant at 8%. Results demonstrated however that the lengthwise Young's modulus for the current composite increment essentially by expanding the aspect ratio (l/d) of Nano-tube while the change in transverse modulus with fluctuating perspective proportion was not exceptionally noteworthy. The results of the simulation have been consequently matched with the Mori-Tanaka model as well as the Finegan model.