A new procedure for virus concentration from water samples has been developed. This method called calcium flocculation-citrate buffer method involves virus flocculation formed by 1 mol/L Ca²⁺ solution and its flocculating agent, virus release with sodium citrate dissolution (0.3 mol/L, pH5.0), and virus reconcentration by ultrafiltration. It can concentrate the viruses 10000 times easily. Seeding experiments showed that it could recover f₂ phage in an average rate of 96%, and 100% for the vaccine poliovirus type 1 (PV₁), which was significant higher than the current positive charged filter method (P<0.05). The established approach is rapid, simple and effective.