Stellerite was activated and organic modified by calcination and hexadecyl trimethyl ammonium chloride (CTAC) to improve its adsorpability of formaldehyde which was one of the iconic pollutants of indoor air pollution. Results showed that the optimum calcining temperature and calcining time were 300 °C and 1.5 h. The optimum amount of anticoagulant, alcohol addition, CTAC addition, bathing temperature and reaction time were 0.5%, 0.7ml, 3 times, 70 °C and 2h, respectively. The organic modified effects of stellerite were characterized by hygroscopicity test, formaldehyde adsorption experiment, scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FT-IR). All data indicated that CTAC had entered into the internal of stellerite and the adsorbability of formaldehyde had a huge improvment after organic modification.