Objective:To establish a RP-LC/ESI-MS combined with HILIC/ESI-MS method for the research of metabonomics. Method: For RP-LC/ESI-MS

the assay was conducted on a Prevail C18 (4.6 mm×250 mm

5 μm). The mobile phase A was 10 mmol·L-1 ammonium formate (adjusted to pH 4 with formic acid) in water

B was acetonitrile-formic acid (99.9∶0.1). A gradient elution mode composed of A and B was used as the mobile phase. For HILIC/ESI-MS

the assay was conducted on a Alltima HP HILIC (2.1 mm×150 mm

3 μm).The mobile phase A was 10 mmol·L-1 ammonium formate (adjusted to pH 4 with formic acid) in water

B was acetonitrile-formic acid (99.9∶0.1). A gradient elution mode composed of A and B was also used as the mobile phase. Electrospray ionization (ESI) in the positive and negative ion mode was used as the ionization source. Nitrogen was used as the nebulizer gas and was maintained at a flow of 11.0 L·min-1 with a nebulizer pressure of 50.0 psi. The fragmentor voltage was set at 275.8 V. Mass spectra were recorded covering m/z 15-2200. Result: Endogenous compounds with different polarity in rat urine could be detected by using RP-LC/ESI-MS and HILIC/ESI-MS. Conclusion: This method could offer a reference for metabonomics study.