Solid-state polymerization of poly(trimethylene terephthalate)(PTT) was carried out to obtain high molecular weight polymers. Two kinds of commercial PTT chips were polymerized in the solid state by the heat treatment at 190~$220^{circ}C$ for various times and they were characterized by end group content, molecular weight, thermal analysis, and X-ray diffraction. In the solid-state polymerization of PTT, the overall reaction rate was governed by the solid-state polymerization temperature and time, and pellet size. The content of carboxyl end groups decreased during the solid-state polymerization with increasing solid-state polymerization temperature and time. The melting temperature and crystallinity of the PTT were higher for the ones treated at higher temperature and longer time. The activation energy for the solid-state polymerization of PTT was in the range of 24~25 kcal/mol for both chips. Through the solid-state polymerization of commercial PTT chips, high molecular weight polymers up to an intrinsic viscosity of 1.63 dl/g was obtained, which corresponded to about a 117,000 weight-average molecular weight.