In order to investigate the influence of tow crimp on the physical characteristics of filter rods, the change of tow’s crimp and its resilience rate in filter rod were analyzed, and their relationships to the weight, draw resistance and hardness of filter rod were studied by taking polypropylene tow of 7.3dtex/5.1ktex as a sample. The results showed that: 1) the crimp of tow in filter rods affected the weight, draw resistance and hardness of filter rod directly. Crimp reduced to some extent in the process of rod forming, however, the crimp reduction in filter rods was more obvious; 2) at a certain denier per filament, the tows of higher crimp needed higher opening ratio; for the filter rods of the same weight, tows of higher crimp resulted in higher filter rod hardness and draw resistance; it suggested that filter rod of the same hardness can be made lighter with tow of higher crimp; 3) there was no direct correlation between crimp resilience and physical characteristics of filter rod.