Abstarct: Nowadays, semiconducting nanostructures have been the subject of great interest due to their unique optical properties. With more investigation and development on such structures; many optoelectronics devices have been fabricated. Materials with large surface-area to volume ratio can be a good candidate in optoelectronics application. In this thesis, we present a low-cost and industrial method to obtain such nanostructures with a chemical vapor deposition method by an electrical furnace. In addition, their structural and optical properties are studied. Different kinds of wide band-gap semiconductors such as zinc oxide (ZnO), tin dioxide (SnO2), and aluminum nitride (AlN) are the main subject of this thesis. These nanostructured wide bad-gap semiconductors show good light emitting properties in blue-green, violet and ultraviolet (UV) wavelengths. Up to now, a large amount of methods have been used to synthesis the wide band-gap semiconductors. Some of the current used methods have problems regarding to high temperature, high vacuum conditions, necessity of using expensive equipments, and difficulties with quality or commercialization. The focus of this thesis is on development of a low-cost method for producing high quality nanostructures in regards to facilities and experimental conditions. This method is baxsed on evaporation of source materials in hot-zone of a horizontal electrical furnace, reacting with an active gas and finally transporting on the substrates in cold-zone of the furnace using a carrier gas. Despite of simplicity of this method, there are a lot of parameters that can effect on growth mechanism. Among of these parameters, the effects of growth conditions such as synthesis temperature, temperature rate, amount of carrier and active gases, source chemical materials, and impurities on structural properties of these nanostructures are studied. The variation of these parameters leads us to systematic modification of one and two dimensional (1D & 2D) nanostructures such as nanowires, nanorods, nanosaws, nanodendrites, nanobelts, and nanosheets. In addition to the structural characterization studies using scanning electron microscope (SEM), transmission and high resolution transmission electron microscopy (TEM, HRTEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX); the optical properties, such as photoluminescence (PL) and nonlinear optical properties (NLO) are studied. Reasonable emission of these structures in the blue-green, violet, and ultra-violet (UV) wavelengths can lead us to fabricate of light emitting devices. Also the effect of structural properties and impurities such as copper and iron are investigated. Finally the NLO properties of ZnO nanostructures are studied using close and open aperture z-scan. Parameters such as nonlinear refractive index and nonlinear absorption coefficient are measured as well as the variation of these parameters with medium temperature are explored. Due to large nonlinear optical properties for ZnO, this material can be a good candidate for application in optical switches and focusing media for laser beams.