[Objective] The aim was to probe into developing changes of spontaneous electrical activities of primordial hippocampus in Bufo bufo gargarizans in postembryonic phase. [Method] Microelectrode technique was used to record extracellularly spontaneous electrical activities of neurons in primordial hippocampus of B.bufo gargarizans in postembryonic phase. [Result] Single, consecutive single, burst, consecutive burst and anomalous spontaneous firing were recorded in primordial hippocampus, in which four kinds of spontaneous firings were recorded in forepart of postembryonic development except the anomalous spontaneous firing, and the burst spontaneous firing and consecutive burst spontaneous firing were predominant. The five kinds of spontaneous firings mentioned were recorded in anaphase of postembryonic development and the single and burst spontaneous firing were predominant.Following with the development of primordial hippocampus, the amplitudes of action potential of single firing and consecutive firing enhanced gradually, and it reaches the maximum in the metamorphosis phase; the differences of the frequencies of consecutive single firing and consecutive burst firing were not significant. [Conclusion] Following with the development of primordial hippocampus, the neuronal electrical activities showed diversification, the developmental degree of the primordial hippocampus in the metamorphosis phase was close to the subadult and adult.
