Objective：To develop and validate a simple HPLC method to determine uric acid（UA），xanthine（Xan），hypoxanthine （Hyp），adenine（Ade） and guanine（Gua） in plasma of normals and the patients with Leukemia and liver cirrhosis. Methods：The separation was performed on Phenomenex C18 column（250 mm×4.6 mm，5 μm），with 50 mmol/L ammonium acetate（pH 4.65）-methanol（99∶1，v/v） as mobile phase isocratic elution，and measured absorbance at 254 nm. Results:Uric acid had good linear rela－tionship in the range of 0.5~200 μg/ml，and the correlation coefficient was 0.999 7；hypoxanthine，adenine and xanthine had good lin－ear relationships in the range of 0.005~0.300 μg/ml，and the correlation coefficients were higher than 0.999 3；guanine had good lin－ear relationships in the range of 0.015~0.300 μg/ml，and the correlation coefficient was 0.997 1. Conclusion：There are significant differences in the concentration of uric acid，hypoxanthine and xanthine in plasma between the momals and the patients with leukemia or liver cirrhosis，while adenine and guanine do not differ significantly.