The article reported four acute ,60,Co radiation accidents involving eleven victims in 1986. The victim of two accidents were evaluated after exposure for 24 hours, while those of other two accidents were determined after exposure for 48 hours. The cytochemical estimation of acid phosphatase and alkaline phosphatase activities in peripheral lymphocyte and granulocyte established in the past were adopted for the estimation of the dose received by the victims. The lowest dose estimated by the acid phosphatase and alkaline phosphatase activities was around 0.10 Gy, but the highest dose evaluated was about 1.90 Gy. The advantages about cytochemical estimation of LAP and ACP activities and the effect of taking radioprotective agent after exposure on the cytochemical estimation of ACP activity were discussed preliminarily.