MXenes, a new family of two-dimensional materials, have recently attracted increasing attention due to their unique properties for a wide range of potential applications. Herein, we synthesize Ti3C2T x /poly(vinyl alcohol) (PVA) composites and investigate the effects of the thermal properties of MXene by temperature-dependent Raman spectroscopy and polarized-laser power-dependent Raman spectroscopy. Compared to the Ti3C2T x MXene, the PVA significantly improves the thermal stability of Ti3C2T x by reducing the thermal coefficient of the Eg 1 mode from -0.06271 to -0.03357 cm-1/K, which is attributed to the strong Ti-O bonds formed between the MXene and PVA polymer confirmed by the X-ray photoelectron spectroscopy results. Meanwhile, the thermal conductivities of Ti3C2T x and Ti3C2T x /PVA composites reach as high as about 55.8 and 47.6 W/(m K), respectively. Overall, this work will contribute to extend the MXene applications in terms of polymer-based nanocomposites and improve the reliability of the related devices effectively.