A nanofibrous web was fabricated by electrospinning poly(trimethylene terephthalate)(PTT). The PTT web with an average diameter of 290 nm was obtained by electrospinning from a 16%(w/v) PTT solution, whereas a PTT film was obtained from solution casting. The water contact angle of the PTT web was much higher than that of the PTT film because the web had a nanofibrous structure with a high surface area and surface roughness. The PTT film crystallized isothermally in the temperature range of $182-231^{circ}C$ and exhibited a multiple melting phenomenon. The degrees of crystallinity of the PTT film and PTT web were 59.2 and $38.7^{circ}C$ respectively. The crystallinity of the PTT web was lower than that of the PTT film because the web solidified rapidly by fast solvent evaporation during electrospinning. To increase the thickness of the web, the spinning solvent was changed to 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). As a result, a nanofibrous web with average diameter of 900 nm and thickness of 0.36 mm was obtained under the same electrospinning conditions. The overall porosity of the nanofibrous web was higher than the microfibrous web. The tensile strength and tear strength of the microfibrous web was higher than those of the nanofibrous web, whereas the breaking elongation of the nanofibrous web is higher than that of the microfibrous web.