Gel content has a certain impact on the immanent quality of rubber products and processing performance. Therefore, it is crucial for brominated butyl rubber to control the gel content. Brominated butyl rubber (BIIR) was prepared by solution method and the effect of the brominated process such as bromination temperature, additives, bromination time and bromide agent on the gel content of BIIR was investigated. The results show that the appropriate reaction temperature is conducive to the control of the gel content. Gel content will increase with the increasing of the concentration of time and bromide agent. The additives can lower the gel content.