Silkworm, Bombyx mori (L.; Lepidoptera: Bombycidae), is an economically important insect, which is sensitive to the environment and susceptible to oxidative damages at high temperature. Low concentrations of TiO₂ NPs (titanium dioxide nanoparticles) can scavenge reactive oxygen species (ROS) produced by oxidative damages in vivo. To explore whether TiO₂ NPs could alleviate oxidative damages of high temperature, the effects of TiO₂ NPs treatment on silkworm growth, the levels of ROS and H₂O₂, as well as the transcription level of antioxidant-related genes were studied at 30°C.These results showed that TiO₂ NPs treatment increased silkworm body weight by 6.0% and reduced the occurrence of irregular cocoon at 30°C. TiO₂ NPs treatment at 30°C decreased ROS levels in fat body and increased expression of Hsp70, SOD by 5.70-fold at 48 h, TPx by 1.61-fold, CAT by 1.81-fold.These results indicated that TiO₂ NPs treatment at 30°C could promote the expression of antioxidant genes and reduce oxidative stress and provide a new method to alleviate high-temperature induced oxidative stress to silkworm.