Numerical simulations of one dimensional unsteady sand saltation process involving aerodynamic entrainment, sand particle motion, splash process and wind-sand coupling interaction present the evolution of wind-blown sand particles under sinusoidal wind variations. Effects of wind frequency/period and amplitude on sand transport rate are discussed. Variations of sand transport rate, wind profile, shear stress and sand number flux from bed with wind variations are shown. The results indicate that sand transport rate increases as wind amplitude increases, whereas decrease as wind frequency increases. The plot of bed shear stress against time shows a rapid decrease before "overshoot" and varies very little after that. The sand number flux from bed however varies periodically with wind.