To retrospectively evaluate the feasibility and efficacy of carbon-ion radiotherapy (C-ion RT) for unresectable bone and soft tissue tumors treated in Gunma University Heavy Ion Medical Center (GHMC). A total 92 patients with bone or soft tissue tumors treated with C-ion RT between November 2011 and December 2018 in GHMC were retrospectively evaluated. In C-ion RT, 70.4 Gy(RBE) was administrated as the standard total dose for sarcomas; 67.2 Gy(RBE) for sacrococcygeal chordomas; 64.0 Gy(RBE) for spinal bone tumors, in 16 fractions over 4 weeks. Local control rate (LCR), survival outcomes, acute and late adverse events were analyzed. The curves of LCR and overall survival rates (OS) were calculated by Kaplan-Meier method. The median age at the C-ion RT was 68 years (range, 25-90 years). Median follow-up time was 28.5 months (range, 1-97 months). Histologically, 31 patients had chordoma, 13 patients had UPS or MFH, 11 patients had liposarcoma, 8 patients had chondrosarcoma and 7 patients had osteosarcoma. The 3-year LCR and OS in all patients were 85% and 70%, respectively. The 3-year LCR and OS of 50 patients with bone tumor were 95% and 82%, and those of 42 patients with soft tissue tumors were 72% and 51%. The 3-year LCR and OS of 31 patients with chordoma were 96%, 90%; those of 13 patients with UPS or MFH were 45%, 62%; those of 11 patients with liposarcoma were 88%, 36%; those of 8 patients with chondrosarcoma were 86%, 67%; and the 2-year LCR and OS of 7 patients with osteosarcoma were 100%, 46%. The 3-year LCR and OS by volume of clinical target volume (CTV) were 100%, 100% in under 100cc (n=6), 76%, 68% in between 100cc and 500cc (n=29), 76%, 37% in over 500cc (n=24), respectively. There were no patients with Grade 3 or above acute adverse events. The Grade 3 or above late adverse events were shown in 7 patients. The results of this study showed that C-ion RT must be an alternative treatment option for unresectable bone and soft tissue tumors. Both the LCR and OS were influenced by CTV volume.