Abstract: 【Objective】 To analyze the effects of the disposal methods of fresh soil sample collection, preservation, extraction and storage of extract on the error of soil nitrate nitrogen and ammonium nitrogen determination results, and explore the ways to reduce errors in measurement results. 【Methods】 Through literature collection, sorting and statistical analysis, the effects of methods of collection, preservation, extraction and storage of leaching liquid on the error of soil nitrate and ammonium nitrogen determination results were comprehensively analyzed. 【Results】 It was so easy to cause the measurement data error that the laboratory measurement procedure had strict error control, and the soil sample collection and preparation link. When soil samples were collected and transported outdoors or at low temperature, the contents of nitrate and ammonium nitrogen in soil would increase. When soil samples were dried by wind or by heat and preserved, the content of nitrate nitrogen and ammonium nitrogen increased. The contents of them by cold storage for a long time would increase, but the change was the least, and the determination results of different extractants and different extraction time would be different, and the way of extraction solution preservation would have a significant effect on the results. 【Conclusion】 The key way to determine the nitrogen content in the fresh soil is to accelerate the sampling speed, sample storage and transportation, extraction and so on. In addition, the method of collecting and preparing soil samples within the error range was also proposed.