[en] The detection method of chromosome aberration is highly valuable as a biological dosimeter to support physical dosimeter. Dicentric is a specific type of chromosome aberration caused by ionizing radiation exposure that can be detected from a radiation dose of 0.2 Gy. To prove this presumption, a research had been conducted by exposing lymphocyte cell of peripheral blood taken from four male donors to Co-60 gamma rays at doses of 0 (control), 0.2, 0.4, 0.6, 0.8, and 1 Gy. The blood samples were cultured with standard procedures. The results showed that dicentric type can be detected starting from 0.2 Gy dose, i.e. 0.002 + 0.001/cell. The higher radiation dose the higher dicentric chromosome induced. The equation of dose-response curve obtained with linier quadratic model is Y = 0.678 x 10-3 - 0.166 x 10-4 X + 0.147 x 10-5 X2 with corellation value R of 0.969