Abstract: The rheological behavior in extensional flow of the melt of mica/polypropylene (PP) blend was researched by twin-bore capillary rheometer and Haul-off equipment. The results show that rheological property of all the Mica/PP samples appear extensional thinning behavior, with the increase of the mica content, the apparent extensional viscosity increases. The extensional stress and the apparent extensional viscosity decline with the rise of temperature. The extensional stress increases, the apparent extensional viscosity and the activation energy of extensional flow viscosity decrease with increasing the extensional strain rate. The added mica particles make the tensile modulus of PP melt increase remarkably, but with the increase of drawing speed, the tensile modulus of the blend melt decreases significantly. In order to improve the spinning stability of Mica/PP blend, it was important to control the drawing speed and processing temperature.