In the study. PP/PTFE composites with different degree of fibrillation were prepared. Crystallization and rheology behavior was investigated. The presence of PTFE fiber enhanced the kinetics of isothermal crystallization of PP. The second modulus plateau at the low ω and a tan δ peak indicates the existence of a three dimensional networks. Extrusion foaming results shows that addition of PTFE increase a 2 orders increase in cell dencity and 10-fold decrease in expansion ratio due to addition of PTFE compared to that of PP. With PTFE nanofiber, open-cell content of the composites was increased.