Most applications of surfactants depend on formation and characteristics of micelle. In this study we measured critical micelle concentration (CMC) of cationic surfactant N, N', N'-polyethylene (10)-N tallow-1, 3-di amine propane (PEG-10 tallow) in aqua solution by using electrical conductivity and surface tension methods. The CMC value of PEG-10 tallow with two different methods was found very close to 1.40 × 10 −3 M with electrical conductivity, and 1.41 × 10 −3 M with surface tension. It also investigated the effect of inorganic salt (NaCl) and pH on micellization of cationic surfactant PEG-10 tallow. With increasing addition of NaCl, formation of micelle structure resulted in a higher CMC. However, at low salt concentrations smaller CMC value was observed comparing the critical micelle concentration of individual PEG-10 tallow. When it comes to the effect of changing pH in CMC of the PEG-10 tallow , it was clearly found that micelle formation or CMC of surfactant was independent on alkaline pH (between 6 and 10), but it was dependent on acidic pH (below 5).