AbstractTo improve the performance of polyvinyl chloride (PVC), composites incorporating polyvinyl chloride (PVC), attapulgite nanoparticles (ANPs), and microcrystalline cellulose (MCC) were successfully prepared. The composites had higher vicat softening temperatures (VSTs) and the MCC had a great influence on mechanical properties of the composites. When MCC was added from 0 to 5 per hundred parts of PVC (phr), the mechanical properties of the composites increased, but the mechanical properties of the composites decreased when the MCC was more than 5 phr. The tensile breaking stress, tensile strength, and impact strength were maximized with increases of 19.76 N (4.1%), 29.66 MPa (15.5%), and 13.8 MPa (7%) when 5 phr MCC was added. Infrared spectral analysis indicated that MCC and ANPs were present in the composites. Scanning electron microscopy showed that the composites system was distributed into two phases, which indicated that MCC in composites was dissolved in the PVC matrix, and some of MCC coated the surface of ANPs as a compatibilizer. Overall, this study provided a promising method for PVC modification to improve its performance.