White spot syndrome (WSS), an epizootic disease, has been prevalent in cultured shrimp in China since 1992and results in high mortality. The economic loss caused by white spot syndrome virus(WSSV) is extensive and has beenharmful to shrimp aquaculture worldwide. Poly-β-hydroxybutyrate (PHB) is a polymer of the short-chain fatty acidβ-hydroxybutyrate. β-hydroxybutyric acid can promote food digestion, nutrient absorption, and protein and mineralutilization. This study was conducted to investigate the anti-WSSV effects of PHB on and relative expression ofnon-specific immune genes in WSSV-infected were supplied with 0.0%(control group), 0.5%, 1.0%, 2.5%, 5.0%, or 10.0% PHB in artificial compound feed at a daily ration of 5.0% bodyweight. After WSSV challenge, survival rates, mean survival time, relative percent survival (RPS), and number ofWSSV copies were compared. The relative expression of the genes that encode superoxide dismutase (were analyzedby quantitative real-time reverse transcription PCR. The results showed that there was no difference in survival ratesamong different treatments (expression levels in 1.0% PHB were higher than that in the control group. The expression level of reached the acme at 6 h, 6 h, 3 h, and 6 h, respectively. After WSSV infection, dropped rapidly within 3 hand then steadily decreased after reaching the acme at 12 h. In addition, the gene expression levels of PHB-fed shrimpswere higher than the control group. Consequently, PHB can help improve immunity and treat WSSV infections.