The pyrolytic behavior of two common wood-derived terpenoids, abietic acid and betulin (i.e., di- and triterpenoids, respectively), was investigated by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Pyrolysis experiments were performed at 600 ^oC and 700 °C using pyrolysis times of 5 s and 20 s, and the influence of these specific variables on the product profiles as well as on characteristic fragmentations was clarified. The results indicated that the pyrolysis products identified (40-50% and 45-65% of the total peak areas for abietic acid and betulin, respectively) were mainly aromatics in nature and only some aliphatic products could be detected. In general, the increased formation of the compounds identified (for both model compounds about 50 individual degradation products) was observed under harsher pyrolysis conditions, and with this respect, pyrolysis temperature seemed to be a more influential parameter than pyrolysis time. Among the typical degradation products, benzene, naphthalene, indene, and mainly their methylated derivatives, were dominant for both feedstock compounds. However, due to the relative chemical stability of the initial phenanthrene-type tricyclic skeleton structure, the characteristic phenanthrene derivatives were formed at low concentrations only from abietic acid.