In the early stage of eutrophication, the coexistence of "grass and algae" in lakes is obvious. Understanding the P sorption-desorption behavior in natural sediments during the ecologically sensitive transition period has important scientific value for predicting the deterioration of lake ecosystems and formulating restoration measures, but the related mechanisms are still unclear. In this study, the analysis results of sedimentary dissolved organic matter (DOM) fractions, extractable Fe (hydr)oxide fractions and P adsorption experiments showed that sedimentary DOM fractions, especially the tyrosine-like protein fractions and microbial humic-like fractions, played a part in determining the EPC