Improvement of sample pretreatment conditions of ion chromatography method of national standard methods to determinate the nitrite and nitrate in meat products. The national standard methods employ filter paper to remove the fat in the sample extract. However, it is found the usage of filter paper can disturb the detection of nitrate, and cause serious high detection results. In this study, using chloroform to remove the fat can efficiently solve the disadvantages exist in the national standard methods. The generally exceed the standard of nitrate in the meats is not caused by the enterprise of illegal use of additives containing nitrate,and it is caused by the usage of spice, which is rich in nitrate, and peppers etc. plant material in the process of machining. Experiments proved that the improved method is simple, rapid, sensitive, accurate and suitable for the quantitative determination of nitrite and nitrate in meat products. Nitrite and nitrate in the measured concentration range showed a good linear relationship with the peak area. The recoveries were between 94.5% and 100.5%. The relative standard deviations were between 0.70% and 3.5%.