Abstract: To reveal the underlining molecular mechanism for the formation of damp and hot constitution, and also promote personalized nutrition for people with that constitution, a dozens of volunteers were recruited to conduct a metabolic research. The volunteers were diagnosed by Chinese physician, and people who were mild constitution as well as damp and hot constitution were screened. Afterwards, the first morning urine was collected and analyzed using ultra high performance liquid chromatography coupled with high revolution orbitrap mass spectrometry (UHPLC-Q/Exactive). Mass spectra were then digitalized into high demission data matrix. Meanwhile, a volcano model and an orthogonal partial least squares discriminant analysis (OPLS-DA) were performed to screen the most relevant metabolites which could discriminate damp and hot constitution. Furthermore, the pathway analysis was conducted to reveal the molecular mechanism for the formation of damp and hot constitution. Result show that there was a significant difference between damp and mild constitution, and 22 metabolites were proven to be significantly different by volcano model. However, 29 metabolites screened by OPLS-DA model were the most relevant with damp and hot constitution. Pathway analysis base on the screened metabolites showed that dysregulation in arginine and proline metabolism, histidine metabolism, glycine, serine and threonine metabolism might account for the formation of damp and hot constitution.