Abstract: Weight-loss on heating of starch was studied in atmospheres of N2 and mixture of N2-O2 (91+9, by vol.) by synchrothermogravimetry. A comparative study on the differences among the thermogravimetric, differential theromogravimetric and ΔT curves obtained was made by analyzing sample under dynamic temperature elevation. The pyrolytic products obtained at 315 ℃ and 350 ℃ in the 2 gas atmospheres were analyzed by FTIR and GC-MS. Totally 51 compounds were identified and determined.