Polymer composites with inorganic fillers such as glass fiber, talc, clay, etc., are industrially important due to their improved properties over the original polymer materials. Interfacial adhesion between matrix and filler is a key factor that influences the properties of composites. Despite numerous studies related to this issue, the details of the mechanisms of interfacial adhesion between matrix and filler are not yet fully understood due to a lack of techniques for characterizing interfacial structure at the molecular level that occur in small areas of the polymer system. Fourier transform infrared (FTIR) microscopic techniques combined with two-dimensional (2D) correlation spectroscopy has been developed as a technique that can probe the chemical structures (formation of interactions and chemical bonds) related with the interfacial adhesion. This paper intends to provide a comprehensive overview of recent progress for visualization techniques of matrix-filler structures of polymer composites using FTIR microscopy.