Polyglycolic acid (PGA) has been used mainly as the absorbable suture materials be cause of its biodegradable properties. The melt polymerization of PGA was investigated as a function of lauryl alcohol content using a torque meter. The torque curve versus reaction time showed a S-shape. PGA melt polymerization showed 3 distinct steps such as initiation, propagation and termination. The reaction time which melt viscosity started to increase on PGA melt polymerization decreased as the lauryl alcohol content increased. Zero-shear viscosity and inherent viscosity slightly decreased up to a 0.3 wt% lauryl alcohol content, but suddenly gave a sudden decrease above that content. Additionally the relation between zero-shear viscosity and inherent viscosity was determined.