Abstract:The inhibition of overwintering cyanobacteria recovery in Taihu Water by gamma-ray irradiation from 60Co was studied, the effects of different absorbed doses and additives (methanol, sodium carbonate) on inhibition were investigated. Gamma-ray irradiation significantly inhibited the recovery of overwintering cyanobacteria, the increasing of absorbed dose enhanced the inhibition effect. The ratio of chlorophyll a, chlorophyll b and phycocyanin, in water with the absorbed dose of 5kGy and 40 days culture, were 8.66%、16.8% and 17.2% to that in control sample, the recovery of overwintering cyanobacteria was inhibited. 0.5% CH3OH、0.22mmol/LNa2CO3 additives restrained irradiation process, with the same absorbed dose and culture time, the chlorophyll a, chlorophyll b and phycocyanin concentration in water sample contained additives were higher than that in control sample.