Update publication information. Gastrointestinal stromal tumor (GIST) is a common sarcoma of gastrointestinal tract (GIT) with high metastatic and recurrence rates, but the proteomic features are still less understood. Here we performed systematic quantitative proteome profiling of GIST from 13 patients classified into very low/low, intermediate and high risk subgroups. An extended cohort of GIST (n = 131) was used for immunohistochemical validation of proteins of interest. In total, 10064 proteins were quantified, covering 61% of the GIT transcriptome from The Human Protein Altas. Out of the 10064 quantified proteins, 4938 proteins were observed in all 13 cases with 518 proteins upregulated and 190 proteins downregulated in tumorous tissues independent of risk rating. Pathway analysis showed that the downregulated proteins were mostly enriched in metabolic pathway, while the upregulated proteins mainly belonged to spliceosome pathway. In addition, 131 proteins showed differentially expressed patterns among GIST subgroups with statistical significance. The 13 GIST cases were classified into 3 subgroups perfectly based on the expression of these proteins. The molecular phenotypes of oncoproteins, tumor suppressors, phosphatase and kinases were summarized, and some important molecules were observed. Immunohistochemical analysis of two phosphatases PTPN1 (n = 117) and PPP2CB (n=113) revealed that the GIST patients with high PTPN1 had low chances of developing metastasis, and the expression of PPP2CB was likely to be associated with GIST risk. Collectively, this work provides valuable information for understanding the inherent biology and evolution of GIST.