Abstract: This paper studied the treatment of low-level radioactive wastewater containing Pu by flocculation processed. The Pu removal efficiencies were investigated using cationic polyacylamine (PAM) with different molecular weights in the presence of MgCl₂. The parameters affecting removal rate, such as flocculant dose, solution pH and organic matter were studied. The optimum conditions are the PAM dose of (0.2-1.2)×10^-6, MgCl₂ dose of 0.8 g/L, and a pH of 12. The content of plutonium in effluent is below 1 Bq/L after treatment, and the removal rate of Pu is higher than 95%. The results show that this method has a significant potential in treating low-level radioactive wastewater containing Pu.