PROBLEM TO BE SOLVED: To provide an aqueous solution of sulfate radical-modified basic aluminum chloride in which a sulfate radical coexists, which can exhibit excellent cohesiveness and is stored stably in a state of an aqueous solution without precipitation and separation.SOLUTION: Provided is an aqueous solution of sulfate radical-modified basic aluminum chloride. The solution contains the sulfate radical in an amount of 1 to 3 mass%. When, inAl-NMR measurement, integral values of peaks at chemical shifts of -4 to -2 ppm, -1 to 1 ppm, 3 to 6 ppm, 8 to 13 ppm, and 60 to 65 ppm are denoted respectively by AS, A0, A4, A10, and A13, and when an integral value of an undetected polymer having a high degree of polymerization is denoted by AP, the following conditions are satisfied with AS+A0+A4+A10+A13+AP being denoted as &Sgr;: 1>A0/&Sgr;≥0.19; 0≤A10/&Sgr;≤0.07; 0≤AS/&Sgr;<0.001; and 0≤A13/&Sgr;≤0.001. Further, a basicity of the solution is in a range of 45 to 70%.SELECTED DRAWING: None
