Abstract: In order to study effect on growing development and yield of oats with different nitrogen fertilizer.Find out the nitrogen levels of suitable oat growth and yield improvement.The study used Dam oat 1 which was introduced in 2005 for the trial materials.The crack with random group was used on the trial design.Through the regular observation and comparative analysis of oats each period form and physiological indices.The results was showed as follow: Significant difference between the growth dynamic index of oats in different nitrogen levels.The plant height will increase with the increasing of nitrogen fertilizer, the leaf area and tiller number too.But if the amount of nitrogen is excessive, Invalid tiller number will be increasing.keeping green affected the output in late growth period.Appropriate amount of nitrogen can make the oats keep normal standard on the physiological and biochemical indicators and improve oats production.When the nitrogen application rate is 144 kg / hm2, Dam oat 1 have a higher yield.