A disperse dyeable polypropylene fiber has been prepared by admixing polystyrene to the polymer prior to extrusion. Polystyrene has been synthesized at suitable molecule weight and narrow mol wt distribution. The dyeability, mechanical properties, shrinkage, degree of crystallinity, and orientation of pure polypropylene or the blend fibers with different amount of polystyrene were investigated. In addition, the structure of the blend containing 4 and 6% polystyrene was also studied to explain the interesting dyeing behavior of the blend fibers.