Abstarct: In this experimental research, we studied the surface morphology, structural, electrical and optical properties of nanostructured zinc oxide (ZnO) thin films under different chemical bath deposition (CBD) conditions for UV. photoconductivity application. For sample characterization various equipment including: Field Emission Scanning Electron Microscopy (FESEM), X-ray diffraction (XRD), Raman Spectroscopy, Ultraviolet-Visible (UV-Vis) spectroscopy and current-voltage (I-V) measurements were used. Synthesis of ZnO thin films consist of two steps: 1- seeding of the glass substrate; 2- synthesis of zinc oxide laxyer on seeded substrate. In the first step, an aqueous acetate solution (Zn(CH3COO)2.2H2O) and pure ethanol; and in the second step, a solution of zinc nitrate (Zn(NO3)2.6H2O) together with hexamethylenetetramine (C6H12N4) (HTMA) and deionized water were used. The investigated variable parameters in this study are as following: the concentration of seed solution (Section 4.2), the effect of annealing temperature on zinc oxide thin laxyer with a substrate of 8 times seeding process (Section 3.4.1), the effect of annealing temperature on zinc oxide thin films with 7 times seeding process (Section 4.2.2), and finally the effect of annealing time (Section 4-4). We found depending on the growth conditions, the FESEM images of the samples indicated the formation of ZnO nanowires. The X-ray diffraction (ZnO) patterns showed all samples have a hexagonal (wurtzite) polycrystalline structure. Also it was found that, in general, band gap of the synthesized samples are varying as a result of crystalline defects (mainly dislocation density and oxygen vacancies). Finally from photoconductivity study of the samples we found that the crystalline defects and surface morphology of the laxyers are very effective on UV. light detection. We found among various studied parameters, the synthesized sample that is grown with a seed solution concentration of 8 mM with 8 times seeding process, and with final annealing temperature of 400 C in 1 h has the highest light sensitivity.