Nitrate and nitrite play an important role in the nitrogen cycle involving the complex interaction of different ecosystems of the biosphere. Both nitrate and nitrite are present in water and food, and that humans are exposed to these ions by these sources. The nitrate in drinking water comes from a variety of sources, many of which are dependent to some extent on human activity and so vary between regions and with time. Nitrate and nitrite are usually added to processed meat products to provide protection against microorganisms that cause food poisoning. Nitrite may react with secondary amines to form nitrosoamines, a In this research, the negative electrospray ionization ion mobility spectrometry (ESI-IMS) has been evaluated for simultaneous determination of nitrate and nitrite. The methodology reported here is very simple and rapid in addition to inexpensiveness for analysis of NO 3 - and NO 2 - without any complicated preparation methods. The ESI-IMS instrument is inexpensive, fast, accurate and sensitive. When compared to methods currently used for nitrate and nitrite analysis, ESI-IMS method has an analysis time shorter them traditional methods. In this methods, the analyte is introduced as a liquid and it is then ionized by Electrospray Ionization sources. Standard solutions of nitrate, nitrite, chloride, formate, and acetate were analyzed using ESI-IMS and distinct peak patterns and reduced mobility constants ( K 0) were observed for respective anions. The IMS response of trinitrotoluene (TNT) using as standard peak that appears at right site of peaks solvent. The identities of the nitrate and nitrite mobility peaks were verified by comparison of reduced mobility constants with that of identified nitrate and nitrite ions reported in literature. In the analysis of binary mixture, no overlapping has been observed between nitrate and nitrite ion peaks. A working range of 3 orders of magnitude were observed. A working range of nitrate and nitrite 5-1000 and 10-1000 µg L -1 were obtained. A linear dynamic range of 2 orders of magnitude of nitrate and nitrite 10-1000 µg L -1 and quantitative detection limits of 10 µg L -1 for nitrate and nitrite were obtained. The limits of detection of 4.7 and 3.8 µg L -1 for nitrate and nitrite were obtained. The calibration plots were linear in the range of 10 to 700 µg L -1 for nitrate and nitrite. The calibration curves showed R 2 value of 0.9910 and slope of 2.70 for nitrate and R 2 value of 0.9925 and slope of 2.89 for nitrite. The relative standard deviations were under 5%. Recoveries were obtained for nitrate and nitrite as higher than 70 %.