Purecell, hydroxyethyl-cellulose-2-hydroxypropyltrimethyl ammonium chloride ether, was developed as a thickener and evaluated its functions for stability and safety when it was added in the cosmetic composition. Compared with a commercially available thickener Natrasol, Purecell have a basic chemical backbone of hydroxyethylcellulose which has been widely used in the cosmetic industry. pH and viscosity of Purecell was lower than those of Natrasol, however, a similar pH value to was shown when the Purecell was added into a shampoo or cream. The Purecell was stable to temperature and light. When 0.5% of the Purcell was added to a shampoo having cationic surfactant, a separation occurred due to the same cationic surfactant of the Purecell and shampoo. However, the shampoo and cream made with Purecell improved a smoothness and adaptability of hair. It also showed a negative response for Patch test of human, indicating the Purecell was safe for use.