Livestock grazing activities potentially alters grassland ecosystem belowground carbon (C) and nitrogen (N) cycles.Although numerous individual studies have been conducted, it remains controversial as to how grazing actives affect the overall direction and magnitude of such alteration.Here, we conducted a comprehensive meta-analysis of 87 published studies to quantify the changes of 19 variables associated with belowground C and N cycles, including their pools,fluxes, C:N ratio and other environmental variables in response to livestock grazing.