Abstract: Based on the hydroponic culture methods, the responses of the biomass, shoot/root ratio, the nitrate reductase activity and glutamine synthetase activity of 3 maize inbred seedlings with different nitrogen use efficiency to 3 levels of light intensity and 3 levels of N supply were studied. The results showed that the difference of the response of the seedling biomass, shoot/root ratio, the nitrate reductase activity and glutamine synthetase activity among 3 maize inbreds was significant. The biomass of maize seedling with lower nitrogen use efficiency was higher than that of maize seedling with higher nitrogen use efficiency under low nitrogen and light intensity condition, but it was lower under high nitrogen and light intensity condition. The root growth of maize seedling with higher nitrogen use efficiency was better that of maize seedling with higher nitrogen use efficiency. The best combination of nitrogen and light intensity for the biomass and nitrate reductase activity were different among 3 maize inbreds with different nitrogen use efficiency and the maize inbrd with low nitrogen use efficiency need less nitrogen or lower light intensity than the maize inbred with high nitrogen use efficiency. In conclusion, the appearance of nitrogen use efficiency for maize inbreds is not only related to the nitrogen supply but also to the light intensity.