This study sought to identify potential bioactive peptides from the placenta that are involved in preeclampsia (PE) to obtain information about the prediction, diagnosis and treatment of PE. The liquid chromatography/mass spectrometry was used to perform a comparative analysis of placental peptides in normal and PE pregnancies. Gene ontology (GO), pathway analysis and ingenuity pathway analysis (IPA) were used to evaluate the underlying biological function of the differential peptides based on their protein precursors. Transwell assays and qPCR were used to study the effect of the identified bioactive peptides on the function of HTR-8/SVneo cells. A total of 392 upregulated peptides and 420 downregulated peptides were identified (absolute fold change ≥ 2 and adjusted P value < 0.05). The GO analysis, pathway analysis, and IPA revealed that these differentially expressed peptides play a role in PE. In addition, the up-regulated peptide "DQSATALHFLGRVANPLSTA" derived from Angiotensinogen exhibited effect on the invasiveness of HTR-8/SVneo cells. The current preliminary research not only provides a new research direction for studying the pathogenesis of PE, but also brings new insights for the prediction, diagnosis and treatment of PE.