Abstract: This paper presents the recent advance in the clinical diagnosis and treatment of acute radiation sickness (ARS):1. The starting time of vomiting, more related to the dose rate is emphisized in early triage. 2. The clinical grading corresponding to the damage to the neurovascular sytem(N1-4), haematopoietic system(H1-4), cutaneous sytem (C1-4)and gastrointesinal system(G1-4)and its integraton of grading code (RC1-4), suggested by European Commission scholars has new idea and also useful for the prognosis and mangement of ARS. 3. IAEA/WHO "How to recognizeaccidental radiation injury and make preliminary response" is useful for the recognition and correct mangement of hazard from orphan radioactive source. 4. The radiation biodosimetry with significance for triage. 5. Further apprehension in the external protracted irradiation induced ARS, SARS and CRS. 6. Supportive therapy including anti-emetic, analgestic, brain edema therapy, adapted nutrition, antibiotic treatment in case of infection, and substitution therapy(thyombocyte concentratrates and erythrocyte concentrates). 7. Conservative skin treatment and surgery. 8. Haematopoeitic growth factor (HGF) therapy (stimulation). 9. Haemopoietic stem cell transplantation (HSCT):indications and contra-indications.10. Recent advance in the experimental dog model and clinical experience denotes that non-ablative PBSCT may be the best choice in accidental most severe ARS.