Due to its adaptability to different climates, different growing times, high photosynthetic capacity, nutrient value, and yield, maize is an important crop that is widely grown all over the world. This study was conducted to determine the grain yield and some nutrition traits of 18 maize cultivars under the ecological conditions prevalent in Bilecik in the years 2019 and 2020.Experiments were carried out in randomized complete block design with three replications. There were significant (P<0.01) differences among the cultivars in terms of grain yield and all quality traits. In addition, there were significant differences between the two years in terms of the investigated traits except for potassium, neutral detergent fiber, and total phenolic and ash content. According to the two year-average; grain yield (TV), test weight (TW), thousand grain weight (TGW), ash (AC), fat (FC), protein (PC), starch (SC), acid detergent fiber (ADF), neutral detergent fiber (NDF), and total phenolic (TP)contents of the maize cultivars were 13.00-ton ha-1, 73.85 kg, 317.76 g, 1.59%, 5.95%, 11.22%, 65.69%, 4.25%, 15.17%, and 7.16 mg GA/g, respectively. The condensed tannin (CT), free radical scavenging activity (DPPH), total flavonoid (TF), potassium(K), phosphorus(P), magnesium (Mg), zinc (Zn), iron (Fe), manganese (Mg), and copper (Cu)contents were 0.39%, 7.97%, 0.48 mg QE/g, 4.24 g kg-1, 3.58 g kg-1, 1.24 g kg-1, 2.36 g 100g-1, 0.96 g 100g-1, 0.67 g 100g-1, and 0.20 g 100g-1, respectively. The highest of grain yield were determined of the maize cultivars of ADA-9510 Larigal, Kerbanis, Keravnos, SY-Inove, Dracma, Kilowatt, ADA-9516 and SY-Gladius. According to the Biplot graph, the cultivars ADA-9510, SY-Inova, SY-Gladius, Kalideas, Dracma, Kerbanis, and Keravnos were prominent in terms of TV, SC, DPPH, TP, NDF, CP. The cultivars Arifiye, SY-Antex, Kolessaus, and Sakarya were prominent in terms of many quality traits such as PC, FC, AC, TF, TW, ADF, K, P, Mg, Fe, Zn, and Mn.