CIRP studies the effects and mechanisms of ionizing radiation on organisms at various levels such as collectives, individuals, tissues, cells, and molecules. CIRP has performed radiation damage effect tests with different LET ionizing radiations such as X-rays, γ-rays, α particles, heavy ions, and neutrons successively. On this basis, three technologies have been established, including the biological technology of occupational health monitoring of radiation worker, the rapid screening and classification technology of irradiated personnel in nuclear and radiation accidents, and the radio-biological dose estimation.