In present study, we showed that absence of MyD88 decreased the resistance of mice to S. pneumoniae meningitis, including more weight loss and worse clinical manifestations, with diminishing neutrophil infiltration and subarachnoid hemorrhage, attenuated production of cytokines (TNF-α, IL-1β, and IL-6) and anti-inflammatory factor (IL-10) in both CNS and peripheral regions. This evidence concerns the gene MYD88 and subarachnoid hemorrhage.