A new photocleavable molecule for laser desorption ionization mass spectrometry (LDI-MS) was designedand synthesized. The molecule exhibited high sensitivity for negative mode MS detection with goodchemical stability. The molecule was successfully applied to molecular tag for (LDI-MS). Kineticmeasurement of the amidation reaction and monitoring of aminolysis of acetylated sugars weredemonstrated with the molecular tag.