titanium dioxide nanoparticles (TiO2NPs) widely are used in animal and poultry industries.Application of these particles can led to apoptosis, oxidative damages, immune/inflammatory responses, histopathological changes and affect transcription, translation, cell cycle and differentiation. Detoxification of endogenous and exogenous toxins is catalyzed by cytochrome P450s (CYPs) in the cell. CYP1A is induced by many of biological contaminants and used as a biomarker in contamination assays. TOJ3 (homolog of MCRS1) behave as an oncogene and plays an important role in Jun-induced cell transformation and tumorigenesis. In the present study, we analyzed probable changes in expression of CYP1A4 and TOJ3 genes of Japanese quail after exposing to TiO2NPs and vitamin E. Semi quantitative RT_PCR results showed that in animals treated with 500 and 1000 mg/kg of TiO2NPs in the diet, after 90 days of feeding, level of expression of both genes significantly increased. Expressions of CYP1A4and TOJ3 genes significantly decreased in diet including 1000 mg/kg of TiO2NPs and 200mg/kg of vitamin E. While only expression of TOJ3 significantly decreased in diet including 500 mg/kg of TiO2NPs and 200mg/kg of vitamin E. Expression of both genes significantly decreased in diet including 200mg/kg of vitamin E. In conclusion, TiO2NPs treatment can change expression of different genes.