Abstract: TGA-FTIR was used to analyze the composition of inorganic matter filled polymer composites. After being milled to a particle size of 0.1-0.5 mm, 13-15 mg of sample was uniformly loaded into the TGA sample trayfor thermal gravimetric analysis at heating rate of 15 ℃·min-1. The thermal decomposed gas was introduced into sample chamber of the Fourier transform infrared spectrometer by nitrogen stream of 50 mL·min-1. The components of the inorganic filler and polymer matrix were identified from the IR spectra.The abundance of each component was determined by analyzing the TGA curves, with RSD of 2.92%. Comparing the Gram-Schmidt orthogonal reconstruction diagrams of the infrared spectrum and the TGA weight loss percentage-the temperature differential curve, the tandem usage of TGA-FTIR was evaluated.