Three glycosidically bond flavor precursors of GGLY, LGLY and MGLY were synthsized by Koenigs-Knorr reaction. TGA and DSC were employed to measure the weight loss and caloric changes of the samples. The results showed the peak temperatures (T-p) measured by TGA were 275.7 degrees C, 339.8 degrees C and 298.9 degrees C, and T-p measured by DSC were 262.1 degrees C, 301.3 degrees C and 291.0 degrees C respectively. Then pyrolysis products of the glycosides were analyzed by on-line Py-GC-MS technology from 200 to 700 degrees C. The results indicated near 300 degrees C was a feasible temperature range for glycosides pyrolysis. The results showed pyrolysis of the glycosides can release specific aromes of their aglycones of geraniol, (Z)-3-hexenol and menthol. Finally the thermal behavior and the thermal decomposition mechanism of these flavor precursors were discussed. The study on the thermal behavior and pyrolysis products of these glycosides would make flavor precursors used to provide specific flavor of aglycones possibly. (C) 2011 Elsevier B.V. All rights reserved.