Due to the crucial role of oxidative stress on the pathophysiology of autism and the concept of synergistic effect, the benefit of the combined extract of purple rice and silkworm pupae (AP1) for autism disorder was the focus. Therefore, we aimed to determine the effect of AP1 on autistic-like behaviors, oxidative stress status, and histopathological change of cerebellum in valproic acid (VPA) rat model of autism. VPA was injected on postnatal day (PND) 14 and the animals were orally given AP1 at doses of 50, 100, and 200 mg·kg(-1) BW between PND 14 and PND 40. The autism-like behaviors were analyzed via hot-plate, rotarod, elevated plus-maze, learning, memory, and social behavior tests. Oxidative stress and the histological change in the cerebellum were assessed at the end of study. AP1 treated rats improved behaviors in all tests except that in hot-plate test. The improvement of oxidative stress and Purkinje cell loss was also observed in the cerebellum of VPA-treated rats. Our data suggest that AP1 partially reduced autism-like behaviors by improving oxidative stress and Purkinje cell loss. Further research is required to identify the active ingredients in AP1 and gender difference effect.