The invention provides a method and a detection kit for identifying nephritis biomarkers. The biomarkers is free mannose, which is obtained by subjecting serum to pre-column 3-methyl-1-phenyl-2-pyrazolin-5-one (PMP) derivatization high-performance liquid chromatography, and a concentration ratio of glucose to mannose. A detection method is pre-column PMP derivatization high-performance liquid chromatography. According to the technical scheme, the method and the detection kit for identifying the nephritis biomarkers have the advantages that the pre-treatment is simple, the analysis time is short, the instrument price is reasonable, the conventional use is met, the operation steps are simple and easy to learn, the detection result is high in accuracy, a normal person and a nephritis patientcan be distinguished by just blood sampling, moreover, the required serum amount is very less, the amount of sampled blood is less than 1 mL, and the like. An obtained result shows that by means of the analysis method, the free mannose and the free glucose in the serum of the nephritis patient can be fast quantified, so that the method and the detection kit for identifying the nephritis biomarkershave significant meaning in studying a relation between the free mannose and the free glucose in the serum and nephritis and finding a novel nephritis clinical detection marker.