Based on different tillage patterns experiment,the maize yield and soil nitrate accumulation have been studied in areas of wheat and maize a year in north China plain.The results showed that the highest yield pattern is plough and the lowest yield pattern is no till.Compared with seedling time,the nitrate content of plough on harvest time was decreased 66.6% from 0 to 180 cm,the rotary tillage was decreased 21.7% and the no tillage was decreased 20.9%.The accumulation peak is related with nitrate leaching loss.There are different nitrate accumulation peak under different tillage pattern,the plough accumulation peak is downmost,whereas no tillage is no accumulation peak.The tillage pattern will be the important approach to the nitrate leaching loss.