Nanofibrous mats were prepared by electrospinning of poly(trimethylene terephthalate) (PTT) with diameter ranging from 200 to 600 nm. Morphology of electrospun nanofiber obtained by changing processing parameters such as solution concentration and their deposition time, was investigated with scanning electron microscope (SEM). Especially, periodic feature of surface roughness, such as diamond-shaped structure, was exhibited as the deposition time increased. In this work, it was shown that this phenomenon might result from polymer chain mobility, which was induced by solvent properties, and point bonding structure. In addition, schematic diagram was introduced to identify the formation of diamond-shape structure in PTT electrospun nanofibrous mats. (C) 2003 Elsevier Ltd. All rights reserved.