The present study aimed to investigate the effect of RNA interference (RNAi) on the inhibition of interleukin (IL)-6 expression in rat cerebral gliocytes. in vitro and rat cerebral traumatic tissues in vivo, as well as the effect of RNAi on cerebral edema. pSUPER vectors containing IL-6 small hairpin RNA (pSUPER-IL-6 1-5) were designed, constructed and transfected into C6 rat glioma cells using cationic liposomes. ELISA was used to select the plasmid with the strongest interference effect. A freefall method was used to generate a rat brain injury model and rats were randomly divided into treatment, empty plasmid and control groups (n=14/group). IL-6 levels, water content and sodium content were determined in the brain tissues at 24 and 72 h post-injury. pSUPER-IL-6 was effectively transfected into C6 cells and was found to inhibit the expression of IL-6 rather than IL-8. The pSUPER-IL-6 1 vector was most effective in inducing RNAi. In vivo, IL-6 levels were observed to be lowest in the interference group and there were statistically significant differences in water and sodium content among the experimental groups (P<0.05). RNAi was found to inhibit IL-6 expression in vivo and in vitro in rat cerebral gliocytes, and the reduction of the IL-6 levels was found to reduce post-traumatic cerebral edema.