Isocitrate dehydrogenase (IDH) is an enzyme family involved in cell aerobic metabolism of tricarboxylic acid cycle. However, the landscape of IDH mutations in pan-cancer has not been fully characterized. Tissue or blood samples were subjected to next-generation sequencing (NGS) for detection the IDH mutation. A total of 28.868 patients from more than 20 solid tumor species were analyzed. 374 cases (1.30%) with IDH mutations were identified. Among all the IDH mutations cases, 80 (21.4%) were biliary tract cancer, 80 (21.4%) were lung cancer, 57 (15.2%) were liver cancer and 42 (11.2%) were colorectal cancer. The most common IDH variant were IDH1 and IDH2 which were discovered in 0.81% cases and 0.47% cases, respectively. TP53, PBRM1 and BAP1 were the most significantly mutated genes in biliary tract cancer which were different from others cancer. Moreover TMB were significantly higher in lung cancer, colorectal cancer and gastric cancer than biliary tract cancer (p= 0.0164, p <0.0001, p= 0.0067, respectively) and biliary tract cancer patients with IDH mutation had lower TMB compared with wild-type IDH. Somatic IDH mutation was found in multiple solid tumors and IDH would be a driver gene in biliary tract cancer.