Polystyrene/alpha-zirconium phosphate (PS/OZrP) nanocomposites were prepared based on the organically modified alpha-ZrP(OZrP) with hexadecyltrimethyl ammonium bromide (C16) by solvothermal technique and solution refluxing. The structure of the PS/OZrP composites was characterized by X-ray diffraction and high-resolution electronic microscopy. The thermal behaviors of the composites obtained were investigated by thermogravimetric analysis. The maximum decomposition temperatures (T(max)) of PS/OZrP nanocomposites prepared by solvothermal method increased gradually from 431 to 458 degrees C with the increase of the OZrP loading from 0 to 20 wt %, and the amounts of the charred residue at 600 degrees C (char wt %) had a remarkable increase from 1.6 to 17.1 wt %, respectively. Moreover, the TG results of the nanocomposites prepared by solvothermal method have more obvious enhancement in the thermal stabilities and especially in the amount of charred residue at 600 degrees C (char wt %), which has a double increase from 4.2 to 8.5 wt % at the content of 10 wt % OZrP than by solution refluxing. All results suggested that the solvothermal method is an effective way for the preparation of PS/OZrP nanocomposites with the intercalated nanostructure, which led to the obviously improved thermal stability. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122: 593-598, 2011