Abstract: The mechanism of biological actions of quercetin was studied by using metabolomic method and biomolecular network. HPLC-MS was used to analyze the serum metabolome in rats of blank group and quercetin administration group rats, and MS data were processed by MATLAB software. With multivariate statistical analysis of serum metabolite profiles, a clear separation among blank group and quercetin administration group was achieved, potential biomarkers were selected according to the parameters of variable importance in the projection (VIP) and identified according to MS information and database retrieval. Four compounds, related enzymes, action targets and metabolic pathways had been confirmed, namely retinoic acid and RARβ, arachidonate and COX-2, 3, 5-diodotyrosine and TPO, uridine diphosphate glucose and PDEs. The mechanism of quercetin enhancing ability of retinoic acid on the induction of RARβ, activating TPO, using as COX-2 and PDEs inhibitor was approved by biomolecular network and related literatures. In this study, a mechanism of multiple biological actions of quercetin was evaluated at the level of the biomolecular network, metabolomics and biomolecular network can be used to investigate the biological effects mechanism of quercetin, which provided a new method to further revealing mechanism of drug action.