OBJECTIVE: To probe into the effects of risperidone combined with prednisolone on core symptoms and inflammatory factors in children with degenerative autism spectrum disorder (ASD) . METHODS: Totally 218 children with degenerative ASD admitted into the First Affiliated Hospital of Xi’an Jiaotong University from Nov. 2018 to Apr. 2020 were extracted to be divided into the prednisolone group and the control group via the random number table, with 109 cases in each group. All children were treated with Risperidone tablets for 12 weeks. On the basis of the above treatment, the prednisolone group was treated with Prednisolone tablets at a dose of 1 mg/d for 12 weeks. Differences of childhood Autism Rating Scale (CARS) scores and autism behavior rating scale scores between two groups were compared at baseline, after treatment of 4, 8 and 12 weeks. Levels of inflammatory factors in two groups were observed at baseline and after treatment of 12 weeks. The adverse drug reactions of two groups were recorded. RESULTS: The CARS scores of the prednisolone group were significantly lower than those of the baseline after treatment of 4, 8 and 12 weeks, and the difference was statistically significant (F = 22. 493, P < 0. 001) . The CARS scores of the prednisolone group decreased significantly over time, and the difference was statistically significant (F =22. 493, P < 0. 001) . Emotional instability/self-harm attack score (F = 3. 347, P = 0. 027), social withdrawal/sluggishness score (F = 25. 173, P < 0. 001), stereotyped behavior score (F = 3. 179, P = 0. 032) and hyperactivity scores (F = 5. 347, P = 0. 003) of the prednisolone group were significantly lower than those of the baseline after treatment of 4, 8 and 12 weeks, and the differences were statistically significant. After treatment of 12 weeks, the interferon-γ (t = 2. 487, P = 0. 020), interleukin-1β (t = 5. 824, P < 0. 001), interleukin-6 (t = 2. 763, P = 0. 011), interleukin-8 (t = 2. 547, P = 0. 018) off the prednisolone group were significantly lower than those of the baseline, with statistically significant differences. There was no significant difference in the incidence of adverse drug reactions between the prednisolone group and the control group[2. 8% (3/109) compared with 0 (0/109), χ2= 1. 352, P = 0. 245]. CONCLUSIONS: Risperidone combined with prednisolone in the treatment of degenerative ASD can significantly improve the core clinical symptoms of emotional instability/self-harm attack score, social withdrawal/sluggishness, stereotyped behavior and hyperactivity, and reduce the inflammatory response of patients with higher safety. [ABSTRACT FROM AUTHOR]