A HPLC method for the determination of concentrations of Cocarboxylase Tetrahydrate was established. The HPLC conditions consisted of a PHENOMENEX Luna C18 column (250mm ×4.6mm i.d., 5μm) with column temperature at 30℃, 0.05mol/L NaH2PO4 -acetonitrile (50:1, v/v) as a mobile phase with flow rate of 1.0mL/min and detection at 235 nm. The calibrated linear curve of Cocarboxylase Tetrahydrate was within 11.40μg/mL~288.00μg/mL with the correlation coefficient of 0.9999. Cocarboxylase Tetrahydrate was completely separated from impurities. This accurate and reliable HPLC method is applicable for the quality control of Cocarboxylase tetrahydrate.