In this work we describe an approach to study the influence of the compatibilizer, maleic anhydride grafted polypropylene (PP-g-MAH), on the miscibility of polypropylene/polyamide-6 blends (PP/PA6) using attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopic mapping. In measurement, the image area for each blend was 100μm×100μm. Different amounts of PP-g-MAH were introduced into the polymer blends, and the miscibility was characterized by the spatial distribution of PA6 in the image based on the corrected absorbance at 1640cm −1 . It was found that small quantities of the compatibilizer could significantly improve the miscibility of the two immiscible polymers. Furthermore, our results proved that blend with 6 parts of PP-g-MAH by weight exhibited an optimal miscibility behavior. This paper demonstrates that ATR-FTIR mapping is a direct method to visualize the miscibility of polymer blends.