PROBLEM TO BE SOLVED: To provide a surfactant composition maintaining liquid properties although containing an anionic surfactant at a high concentration, having excellent foaming properties and being stable in a long term.SOLUTION: Provided is a liquid surfactant composition containing more than 40 mass% but not more than 70 mass% of an anionic surfactant, 1-10 mass% Quillaja extract and 1-30 mass% polyol, where the anionic surfactant is preferably polyoxyethylene alkyl ether sulfate and the polyol is preferably 1,3-butylene glycol. Further preferably, the composition contains 1-5 mass% cationic surfactant.