To develop dyeable isotactic polypropylene (iPP) fibers, superfine down powder (SDP) was coated on the surface of iPP fibers post melt-spinning. Optical micrographs showed that the surface of powder-coated iPP fibers was roughness, and the amount and dispersion of coated SDP were found entirely dependent on melt-spinning temperature. With the increase in coated SDP content, the moisture and water absorption of powder-coated iPP fibers increased. Powder-coated iPP fibers could be, respectively, dyed by reactive red dye and acid red dye, and the observed enhancement of color strength ($K/S$) and red value ($a^*$) of powder-coated iPP fibers could be attributed to SDP coated on iPP fibers. It was worth noting that the removal of coated SDP affected the wet-washing fastness of powder-coated iPP fibers largely. In addition, the powder-coated iPP fibers were produced in a few minutes with lower cost and could have potential applications in textile industry.