The umbilical cord cell system connects the developing embryo to the placenta. The umbilical cord arteries carry deoxygenated blood and waste from the embryo to placenta; while the umbilical cord vein supplies oxygenated and nutrient-rich blood to the fetus. Endothelial cells and smooth muscle cells are essential components necessary for normal umbilical cord function. Abnormal cell proliferation and regulation within the umbilical cord system can contribute to the development of umbilical cord abnormalities. We offer 4 types of normal human primary cells in the umbilical cord cell system including: umbilical vein endothelial cells, umbilical artery endothelial cells, umbilical vein smooth muscle cells, and umbilical artery smooth muscle cells.