Abstract: The interaction between polyacrylamide (PAM) and sodium dodecyl sulfate (SDS) has been studied in terms of the solubilization of dimethylaminoazobenzene (DMAB). The solubilizing power of SDS becomes greater with the addition of PAM, the extent depending on the molecular weight. The amount of solubilized DMAB increases with the raising temperture. On adding NaCl in SDS solution, the solubilization ability increases, but in SDS-PAM solution, decreases. Thus it is deduced that DMAB taking neutral form solubilizes in the core of micelle in SDS solution and taking acidic form solubilizes on the palisade of micelle in SDS-PAM solution.