Human blood plasma is a complex which communicates with most parts of the body and reflects changes in the state of the organism, therefore identifying age-related biomarkers can help to predict and monitor age-related physiological decline and diseases, as well as to find new treatments for diseases. In this study, TMT-LC-MS/MS was utilized to screen for the differentially expressed plasma proteins in 118 healthy adults with different ages. Participants were divided into three groups: 21-30 (Young), 41-50 (Middle) and ≥60 (Old), the number of differentially expressed proteins when Young vs Middle, Middle vs Old and Young vs Old were 82, 22 and 99, respectively. These proteins were found to be involved in numerous physiological processes such as “negative regulation of smooth muscle cell proliferation” and “blood coagulation”. Meanwhile when Young vs Middle or Old, “Complement and coagulation cascades” was confirmed the top enriched pathway by KEGG pathway enrichment analysis. Functional phenotyping of the proteome demonstrated that the plasma proteomic profiles of Young adults were strikingly dissimilar to the Middle or Old adults. The results of this study mapped the variation in expression of plasma proteins, and provided information about possible biomarkers/treatments for different kinds of age-related function disorders.