Liana constitutes an important structural and functional component in many forest ecosystems and has profound impacts on forest carbon (C) cycling. However, whether and how liana regulates spatial distributions of litterfall and soil organic C are still poorly understood. To address this critical knowledge gap, we investigated litterfall composition and soil physicochemical characteristics in stands with different densities of liana (Trachelospermum jasminoides (Lindl.) Lem.). Both fresh and decomposed leaf litters were greater in the stands with high density of the liana species T. jasminoides. More liana covered stands also had higher soil respiration rate, soil organic C, and total nitrogen than those with less liana. The findings demonstrate that understory liana can regulate litterfall distribution and thus soil organic C, suggesting that the influences of understory liana on belowground ecological processes should be considered while assessing the role of liana in forest ecosystems.