We have previously demonstrated that kudzu root extracts have a hypocholesterolemic effect on rats fed diets high in fat and cholesterol. To further elucidate the mechanism involved, in this study we investigated the effect of water extracts of kudzu root, Pueraria radix, on the production of apolipoprotein B$_{100}$ (APo B$_{100}$) in HepG$_2$ liver cells and secretion of apolipoprotein B$_{48}$ (Apo B$_{48}$) in Caco$_2$ cells. Human cell lines, HepG$_2$ liver cells and Caco$_2$ intestinal epithelial cells, were grown with various concentrations (0%, 0.5%, 1.0%, 1.5%, 2.0%) of water extracts of kudzu root in the media. The kudzu root extract decreased Apo B$_{100}$ production and secretion. Treatment of HeP G$_2$ cells with the kudzu root extract also significantly decreased the intracellular total and free cholesterol concentration, and also decreased esterified cholesterol but was only significant at the highest dose of 2%. Apo B$_{48}$ production, but not secretion, from enterocytes was lowered by the kudzu root extracts. This research provided evidence that the hypocholesterolemic properties of kudzu root may be a consequence of decreased production and secretion of Apo B$_{100}$ in the liver and Apo B$_{48}$ in the intestine.