Soil nailing is a wide used excavation retaining system for excavations in urban areas surrounded by major structures and infrastructures. Soil nail walls are technically feasible and, in many cases, a cost-effective alternative to conventional retaining walls used in top-to-bottom excavations in temporary and permanent applications. In this paper, parametric study using finite element program, PLAXIS 8.2, had been introduced to investigate global factor of safety, F.S, horizontal displacement, Dh, and maximum tension force of reinforcement element, ,as a function of aspect ratio (L/H) of non-uniform soil nail wall. Aspect ratio (L/H) had been varied in four different patterns for non uniform soil nailing structures. In this study we have four patterns (A,B,C,D) for non uniform soil nail walls. Pattern (A): The length of nails (with lower two thirds of the wall is constant while, the length of nails with upper third is varied from 0.25 to 1 from the height of the wall, Pattern (B): The length of nails (with lower two thirds of the wall varied from 0.25 to 1 from the height of the wall, while the length of nails with upper third is constant, Pattern (C): Nail length decreases gradually with depth such that average nail length equal 0.7H or H, and Pattern (D) Nail length increases gradually with depth such that average nail length equal 0.7H or H. The results indicated that increasing aspect ratio increases the global factor of safety of soil-nail walls, it has a significant effect on the maximum tensile force, and negligible effect on horizontal displacement when the aspect ratio is more than 0.7. Also, it was noticed that the position of maximum horizontal displacement is located at two thirds of the wall height from the wall base. In addition, the wall failure took place when the aspect ratio is less than 0.4 in the upper half of wall and the lower half was constant (Pattern A) for all nail lengths we used in this study . Also, the factor of safety was less than the minimum value (1.5) when aspect ratio is 0.25 in the lower half of wall and the upper half was constant (Pattern B). In Patterns (C,D) have a negligible effect on horizontal displacement and the safety factor was increased due to the arrangement of gradual nail length.