Background. Xieriga-4 decoction (XRG-4) is a classic prescription Mongolian medicine that has potent diuretic and anti-inflammatory activities. However, its functional components remain unknown. Purpose. This study aimed to identify the chemical components in XRG-4 and its metabolome in vivo. Methods. An ultra-performance liquid chromatography coupled with a quadrupole time-of-flight tandem mass spectrometry based approach was proposed to systematically profile the chemicolome and metabolome of XRG-4. Result. A total of 106 constituents were identified in XRG-4. Eighty-nine components were identified in biological samples, including 78 in urine (24 prototypes and 54 metabolites), 26 in feces (19 prototypes and 7 metabolites), and 9 in plasma (5 prototypes and 4 metabolites). In other tissues, only a few compounds, including alkaloids and iridoids, were detected. Conclusion. This comprehensive investigation of the chemical and metabolic profiles of XRG-4 provides a scientific foundation for its quality control and administration of clinically-safe medication.