Shikimic acid is an important product in the synthesis of the anti-influenza drug osseltamivir phosphate. LC-MS method was applied for the determination and quantification of shikimic acid from Vietnamese star anis (Illicium verum .). Using the instrument system LC/MSD Agilent series 1110, separation was performed on a Zorbax SB-C18 RP ( mm) column with water containing formic acid and methanol as mobile phase. Analytes were detected both by DAD at 210 nm and by MS detectors. Analytical results showed the percentige of shikimic acid in dried Vietnamese star anis obtains from to .