OBJECTIVE： To study the effects of grape seed proanthocyanidin （GSP） on the transmembrane transport of sodium glycocholate （GA） and sodium taurocholate （TA） in colon glandular cell Caco-2. METHODS： Caco-2 model was used， and RP-HPLC was conducted to determine the contents of GA and TA in cell culture medium. The test was divided into GSP group， GA group， TA group， GSP+GA group and GSP+TA group， the transport volumes of transporting GA and TA from Transwell apical （AP） side to basolateral （BL） side by Caco-2 cell at 0， 2， 4， 8 h were detected， respectively. RESULTS： The linear ranges of GA and TA were 0.05-1.2 mmol/L （R2＝0.999 9）. With the time passing， transport volumes of GA and TA in BL site in GA group and TA group were sharply increased； while the transport volumes were obviously decreased after adding GSP， with statistical significance （P＜0.01）. CONCLUSIONS： GSP has inhibitory effect on the transmembrane transport of GA and TA in Caco-2 cell.