维生素A是最早发现具有生现活性的维生素之一，它在视觉及生理过程中发挥作用。维生素A及其衍生物合称为维生素A族化合物（Retinoids）。二十年代发现维生素A的缺乏可引起磷状上皮细胞的过度角化，甚至发生肿瘤。近年来发现此族化合物有抑制肿瘤细胞生长、增殖，抑制化学诱癌， Vitamin A is one of the earliest discovered active vitamins, it plays a role in the visual and physiological processes. Vitamin A and its derivatives collectively known as the vitamin A compounds (Retinoids). Twenties found that the lack of vitamin A can cause phosphorylation epithelial cells hyperkeratosis, and even the occurrence of tumors. In recent years, this family of compounds found to inhibit tumor cell growth, proliferation, inhibition of chemical induced cancer,