Abstract: To study the toxic effect of aluminum on Human embryonic osteoblastsin vitro.The Human embryonic osteoblasts were divided into three groups(control,low and high Al groups).The growth,development and morphology of osteoblasts were observed by the light microscope.The results showed that the survival cell quantity in high Al group was remarkably lower than those in the control and low Al groups(P<0.05),and the detective rate of cell degeneration and necrosis was more than those in the two groups(P<0.01).We concluded that the growth and development of Human embtyonic osteoblasts was inhibited in high Al group and the high dose Al can result in certain toxicity for Human embtyonic osteoblasts.