The pyrolysis of softwood (SW) kraft lignin was examined at 400, 500, 600, and 700 degrees C. The yields of pyrolysis oil, char, and gas were determined to be 35-44%, 57-38% and 8-18%, respectively. The pyrolysis oil has a comparable heating value with ethanol and coal. The elevated temperature of 700 degrees C was found as the point of primary decomposition of lignin and the secondary decomposition of pyrolysis oil. Gel permeation chromatography (GPC) and quantitative C-13 and P-31 NMR were used to characterize the pyrolysis oil. A C-13 NMR database was created to provide a more accurate chemical shift assignment database for analysis of pyrolysis oils. On the basis of the results of C-13 and P-31 NMR for the pyrolysis oil, aliphatic hydroxyl, carboxyl, and methoxyl groups are eliminated during pyrolysis. Cleavage of ether bonds in lignin was also shown to be a primary decomposition reaction occurring during thermal treatment. The results of GPC analysis indicated that lower pyrolysis temperatures yielded a bio-oil that had a lower molecular weight and lower polydispersity value.