The present invention relates to an Agathobaculum sp. strain having a preventive or therapeutic effect on autism spectrum disorders and a use thereof. As a result of orally administering an intestinal microorganism, the Agathobaculum sp. strain of the present invention to valproic acid (VPA)-induced autism model mice and BTBR autism model mice, the Agathobaculum sp. strain exhibits an effect of remarkably alleviating autism spectrum disorders including repetitive behavior, hyperactivity, difficulties with social interaction, and cognitive/memory impairment behavior, compared to a non-treated control. Therefore, the Agathobaculum sp. strain can be usefully used in food, medicine, or feed for preventing or treating autism spectrum disorders, thereby being very useful for related industries.COPYRIGHT KIPO 2019