In this dissertation the three dimensional structure of the electrospun fibrous scaffold was simulated using an image modeling technique. Fabricating Poly(3-hydroxybutyrate) scaffolds according to a Taguchi experimental design, both the processing parameters as injection Flow rate, applied voltage and nozzle-collector distance and the material parameters as the Polymer concentration, volatility and conductivity of the solution were investigated. having assessed the scaffolds architectural characteristics as the porosity, pores numbers, pores size, pores interconnectivity and webs permeability indices (WPI), all the control parameters were then optimized. The applicability of a unique deduced criterion called “Scaffolds Percolative Efficiency” (SPE) was validated with the in vitro culture of mouse fibroblast cells on the structurally distinguished scaffolds. The structurally optimized scaffold matrix was then reinforced with up to 15%wt natural Hydroxyapatite nanoparticles. Mechanical and physical properties of the resulted Bio-Nanocomposite scaffolds were characterized with the help of tensile test and FTIR spectrophotometer and scanning electron microscopy with which the most desired mechanical and bioactivity properties was obtained when up to 8%wt of Hydroxyapatite nanoparticles was present.