Phenolic compounds occur ubiquitously in plants and are active components in many herbs. Numerous studies have shown that these phenolic compounds possess antioxidant, anti-carcinogenic, anti-inflammatory and anti-viral activity. The recent research results of some new antioxidant formations from (-)-epigallocatechin gallate, a polyphenol in tea catechin, in mild alkaline fluids has led to the metabolic mechanistic study of these biologically active polyphenolic compounds. In our study, chlorogenic acid, a widely spread polyphenolic compound in plants, was incubated in different pH buffer solutions at physiological temperature for various times. It was found that under alkaline conditions some degradation products were formed from chlorogenic acid. The degradation products were isolated and characterized by LC/MS and NMR techniques. Kinetic degradation study of chlorogenic acid has been performed.