Maintenance of soil organic matter (SOM) in forage ecosystem has long been recognized as a strategy to reduce soil degradation. Tall fescue management that can increase SOM will consequently improve soil aggregation. One objective of this study was to investigate the impacts of endophyte-infected and endophyte-free tall fescue on the distribution of soil carbon pools: total organic C (TOC), microbial biomass C (MBC), particulate organic C (POC), and C storage in soil aggregates. A second objective was to compare the ratio of macroaggregates to microaggregates. The experiment was conducted in Maury silt loam, Kentucky at the depths of 0-7.5, 7.5-15, 15-22.5 and 22.5-30 cm. In general, endophyte infection of tall fescue played a role in soil structure development, with more soil organic matter, a greater proportion of macroaggregates, and increased C sequestration, but the effects were varied with depth. Detailed findings will be presented and discussed.