This paper focus on removal of cationic dyes methylene blue (MB) and crystal violet (CV) fromaqueous solution by using anionic surfactant modified laterite soil. The BET surface area and the pointof zero charge of the material were determined as 54.02 m2/g and 5.73, respectively. The FT-IRspectras of the material after sequential adsorption of MB and CV were studied. The concentration ofMB and CV was measured by molecular absorption spectrometry method. Some optimum conditions formeasuring MB and CV by the method were systematically studied and found as wave length 663 nm,pH 2 for MB
590 nm, pH 3 for CV. The results indicated that some ions such as Fe3+
Al3+
Ca2+
Zn2+... reduced MB and CV adsorption capacity of the material. The removal efficiency of MB and CVusing SDS modified laterite soil is always higher than that using laterite soil. Fixed – bed columnadsorption capacity for MB and CV is 11.26 mg/g và 13.66 mg/g (at flow speed of 2.0 mL/min and MBconcentration is 14.09 mg/L
CV concentration is 16.05 mg/L), respectively. The solution of 0.01 MHCl was used for elution MB and CV with effective elution is greater than 95%. The MB content of awaste water sample is removed.