Spatially patterned or aligned nanofiber mats have attracted broad attention in many applications. Here, we present a direct fabrication technique of spatially controlled nanofiber mats on various dielectric polymers via a selective pattern of electrolyte solution, without the use of a metal collector. A site-selective hydrophilic pattern on a dielectric polymer surface was obtained through plasma surface treatment with an adhesive tape mask, thereby achieving a selective wetting pattern of electrolyte solution on a 2D flat and even 3D curved polymer surface. The electrolyte solution served as a temporal collector during electrospinning, which enabled not only to form spatially patterned or aligned nanofiber mats but also to spontaneously integrate them with the polymer surface by readily removing the electrolyte solution. This process holds great potential in biomedical engineering, exemplified by the creation of nanofiber topography-imposed polymer surfaces to pattern or align the cells on nanofiber mats.