Abstract: Polypropylene/ramie fiber (PP/RF) composites were prepared by melt blending. The effects of the fiber surface modification were assessed by electronic universal testing machine, scanning electron microscope (SEM), differential scanning calorimeter (DSC), HDTVICAT tester, and coefficient of linear expansion tester. When RF was modified, the impact strength and Vicat softening temperature of PP/RF composites was improved, and crystallinity and linear expansion coefficient decreased gradually. The crystallinity was the lowest in all the studied samples when RF was treated with POEgMAH. While RF was treated with alkali, the linear expansion coefficient was the smallest.