en تنش شوري Salt Stress پژوهشي Research <strong>In this study, rapeseed Okapi cultivar was treated under three NaCl levels (0, 50 and 100 mM) and four Zinc oxide nanoparticles (ZnO NPs) concentrations (0, 20, 40 and 80 mgL^-1) at flowering stage. The experiment was performed in</strong><strong> a completely randomized design (CRD) in </strong><strong>the greenhouse</strong><strong> of Biology Department of Urmia University, in 2015</strong><strong>. Results showed that </strong><strong>NaCl (100 mM) </strong><strong>significantly enhanced </strong><strong>total phenolic, flavonoids, </strong><strong>anthocyanin and phosphorus contents </strong><strong>and increased </strong><strong>ability to scavenge the DPPH radical scavenging activity. Treatment with ZnO NPs (80 mgL^-1) significantly elevated total phenolic and decreased anthocyanin, phosphorus and zinc contents and seed weight</strong><strong>. Foliar application of ZnO NPs ameliorated the negative impacts of NaCl by reduction in phenolic, anthocyanin and phosphorus contents and elevation in seed oil content (20.82%) and seed weight (79.28%) at 50 mM salinity and 20 mgL^-1 of ZnO NPs compared to</strong><strong> NaCl (50 mM) alone</strong><strong>. </strong><strong>In conclusion, foliar application of </strong><strong>ZnO NPs at 20 mgL^-1</strong> <strong>is recommended to farmers as replacement for fertilizers to</strong><strong> alleviate the adverse effects of salinity stress.</strong> antioxidant activity, Brassica napus, salt stress, secondary metabolites 11 18 http://jispp.iut.ac.ir/browse.php?a_code=A-10-69-4&slc_lang=en&sid=1 Torfeh Akhavan Hezaveh torfeha@yahoo.com No Urmia University Latifeh Pourakbar l.pouakbar@urmia.ac.ir Yes Urmia University Fatemeh Rahmani f.rahmani@urmia.ac.ir No Urmia University Hadi Alipour Ha.alipour@urmia.ac.ir No Urmia University