<p>Nitrate (NO₃⁻) and ammonium (NH₄⁺) are two major nitrogen (N) sources for plants, and the preference for N forms was tested in oilseed rape genotypes with contrasting N utilization efficiency (NUtE). In this experiment, one high NUtE (Nt-efficient) and one low NUtE (Nt-inefficient) oilseed rape genotypes were fed with NO₃⁻ or NH₄⁺ in hydroponic culture, and the biomass, N accumulation, photosynthetic characteristics, activities of N metabolism enzymes (nitrate reductase (NR), glutamine synthetase (GS), glutamate synthase (GOGAT) and glutamate dehydrogenase (GDH)), root characteristics and expression of <i>BnNRT1.1</i> and <i>BnNRT2.1</i> were measured. The results showed that both Nt-efficient and Nt-inefficient genotypes fed with NO₃⁻-N had significantly greater shoot biomass, net photosynthetic rate, GS and GOGAT activities in leaf and root, and <i>BnNRT1.1</i> and <i>BnNRT2.1</i> transcript levels in leaf. Regardless of N source, the Nt-inefficient genotype had significantly higher shoot and root biomass, N accumulation, net photosynthetic rate, transpiration rate, NR, GS, GOGAT activity, primary root length and root activity, and <i>BnNRT1.1</i> expression levels in leaf and root than the Nt-efficient genotype. These results suggested that NO₃⁻-N is the preferred N source for both Nt-efficient and Nt-inefficient oilseed rape genotypes and that the Nt-inefficient genotype has stronger growth attributes than the Nt-efficient genotype at the vegetative growth stage.</p>