Abstarct: In the current research shape optimization of structures considered as an important part of structural optimization. It has been done baxsed on the isogeometric analysis approach which has the advantage of using powerful representation capabilities of CAD systems baxsed on shape parameterization technique of Non-Uniform Rational B-Splines (NURBS) . Several mathematical programming techniques can be used to solve optimization problem. Between two mainly approach of gradient-baxsed and gradient-free algorithms we used gradient-baxsed method of moving asymptotes (MMA) which is widely used in many recent works. As an inseparable part of gradient-baxsed methods sensitivity analysis carries the burden of accelerating of optimization algorithm. Hence formulation of these derivatives baxsed on isogeometric has been considered. Isogeometrical shape optimization of two dimensional structures considered in 2008 for the first time by wall et al. but 3D sensitivity analysis formulation and 3D shape optimization of structures which has many applications in the elasticity problems has been presented in this thesis. Finally some 2D and 3D elasticity problems has been solved in the last chapter to verify formulation results and methods.