The aim of this work is the preparation and properties of poly 2-thiozyl methacrylamidevinylbenzyldimethyloctadecylammonium/montmorillonite (TMAAm-VBOA/MMT) nanocomposites. Firstly 2-thiozyl methacrylamide (TMAAm) monomer was synthesized by reacting 2-amino thiazole with methacryloyl chloride in the presence of triethylamine. Synthesis of nanocomposites were performed in three steps which are; purification and cation exchange capacity (CEC) determination of clay, preparation of organoclay and synthesis of nanocomposites. Nanocomposites with various amounts of TMAAm and VBOA/MMT were synthesized through in-situ and free radical polymerization using benzoyl peroxide as an initiator. Changes in the structure of the nanocomposites were examined through Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD) and scanning electron microscopy (SEM). Additionally, thermogravimetric analysis and BET analysis were conducted to investigate the thermal properties and particle size distribution of the nanocomposites. The results of X-ray and SEM analysis suggest that the exfoliated structure of the new nanocomposite materials. In addition, the thermal decomposition temperatures of nanocomposites were found to be higher than that of pure organoclay and poly(TMAAm) and thermally degradation rate decreased.