Aim To establish a cell cultured container with the condition of carbon monoxide (CO) or hypoxia (H) and to explore the effects of CO and hypoxic on rat aortic endothlial cell (RAEC). Methods By the use of drawing-charging method to obtain desired gas concentration in the container in a reletively short time, and ultrastructural features of RAEC was observed by transmission electron microscopy. Results 1) The concentration of CO and O 2 in container can reach the necessariexia, the typical constituents of mitochondria, vesicles, endoplasmic reticulums, neclei and cytomembrane was seen in RAEC. But there are large vacuoles increased,swollen and brolen mitochondria occurred only some of cells. Many lipid bodies formed in cells. Cell surface blebbing and many vacuoles could be seen in some cells. Chromatin was located to the rim in the neclei. Intercellular conjection was obviously separate. After 12 h of low-density carbon monoxide (1% CO) compund hypoxia, intercellular conjection was lightly solitary,a few vacuoles architectionics was seen in cytoplasm, and few chromation rimmed in the nuclei. [WT5”HZ]Conclusion The cell architectionics and conjection was injured in hypoxia, And cell injured level decreased in low-density CO compound hypoxia.It suggest that low-density CO can partly protect RAEC from being damaged by hypoxia.