TurboID, a mutant biotin ligase, based proximity labeling method is a new efficient technique for recognizing protein-protein interactions and has been successfully applied to living cells. Sialic acids are typically the terminal monosaccharides attached to many glycoproteins and play many important roles in many biological processes. However, the lack of enrichment methods for terminal sialic acid glycosylation in vivo hinders the identification and analysis of this glycosylation. Here, we introduced this technique to identify terminal sialic acid glycosylation in living cells. SpCBM, the carbohydrate-binding domain of sialidase from Streptococcus pneumoniae, was fused with TurboID and overexpressed in HeLa cells. After streptavidin-based purification and detection by mass spectrometry (MS), we identified 41 terminal sialic acid N-glycosylated sites and 3065 putative terminal sialic acid glycosylated proteins which many of them were located in cytoplasm and nucleus.