Background: The etiological mechanism of hypospadias is multifactorial and may be heterogeneous by severity. To date, very limited analyses on proteome in hypospadias have been conducted, and there are still no severe hypospadias proteomics analyses.Methods: In our study, tandem mass tag (TMT)-based quantitative proteomics was performed, exploring the clinical samples from hypospadias patients and healthy donators, in order to identify distinctly expressed proteins for severe hypospadias. To further uncover the mechanistic links in these complex proteomics data, we performed several core ingenuity pathway analyses (IPA) to predict, based on these observed different expression of proteins (DEPs).Results: Compared with the unaffected controls, 299 proteins were found to be down-regulated and 176 proteins up-regulated in severe hypospadias foreskin tissues. Functional annotation revealed that these DEPs were mainly in the extracellular space and were associated with complement activation and coagulation cascades. Similarly, the IPA core analysis revealed enriched pathways of the acute phase response signaling and complement system, demonstrating that by mediating their targeted, differentiated expressed proteins