Objectives: Next of Micro- particles reach to nano-particles that the changes some physical properties. For understanding biological processes at the nanoscale, nanotechnology development is needed. An increase in antibiotic resistant bacteria in poultry industry and health products looking for a solution without use of antibiotics. Zinc is an essential element in virtually all cells of the body on the other hand nano zinc oxide in the high concentrations caused cytotoxic effects and death. Materials & Methods: In this study the effects of zinc oxide nanoparticles on hematological parameters and relative weights of carcass components in laying quails were studied. Seventy five laying Japanese quails in a completely randomized design with 5 treatments of female quail (levels ppm 0, 20, 60, 180 of zinc oxide nanoparticles and control group included 60 ppm common form of zinc) and 5 replicate groups (each repeated three birds per cage) were investigated. An observation using SAS software and statistical analysis using GLM ANOVA and Duncan’s multiple range tests were used to compare means. Results & Conclusion: The results showed that the serum concentration of calcium and phosphorus were significantly lower (P< 0.05) in groups that fed 60 and 180 ppm nanoparticles as compared with control but there isn`t any difference between 10 ppm nanoparticle and control groups. The creatine phosphokinase at levels of 180 ppm 60 ppm and serum zinc levels at 180 ppm significantly (P< 0.05) were higher than the control group. No significant differences in other blood parameters were observed between the control and experimental groups. The results of this study suggest that the common form of zinc can be replaced by zinc oxide nanoparticles in diet of laying Japanese quail.