Abstract: The devalopment of medulla oblongata of prenatal goat was observed by HE method. The results were as follows: (1) It is the sixth week in the embryo of goat that the medulla oblongata was in the last stage of the histogenesis of never tissue and in the starting stage of the forming of gray nucleus. So it is the keystage of the development of those gray nucleus in medulla oblongata. (2) The increased number of ripe neurons showed that the variationnal rule of different neuron body are identical in the same gray nucleus in spite of the time of their morphological changes were inconsistent in different gray nucleus. In addition, the bigger difference in time of developmental change of neuron among different nucleus was adapt to their structural characteristics. (3) The forming time was incompletely consistency with the developing time of neurons in the medulla oblongata. Some structure occur early and the neurons emerge lately such as the inferior olivary complex, spinal nucleus of trigeminal never and nucleus of solitary tract. Some structure occur lately, and the neurons emerge earlier, such as the hypoglossal nucleus, nucleus ambiguous and reticular formation. Some structure occur early and the neurons also emerge early such as the dorsal nucleus of vagus nerve.