Muscle Stem Cells or satellite cells (SCs) are required for muscle regeneration. In resting muscles, SCs are kept in quiescence. After injury, SCs undergo rapid activation, proliferation and differentiation to repair damaged muscles. The transcriptome alteration during SC activation is well characterized. While transcriptome is not exactly represent proteome because of post-transcriptional regulations such as miRNA induced gene silencing. However, little is known about SC proteome. We obtained in vivo activated SCs (ASCs) from 3 days post injured muscles for high resolution mass spectrometry Bruker timsTOF Pro. Compared with QSC proteome,, we identified the pathways that are differentially expressed between them.