China has experienced enormous changes in land use in recent decades, which are largely driven by its unparalleled economic development. We analyze changes in vegetation and soil carbon storage between 1990 and 2010 resulting from combinations of land-use category conversion and management. Results demonstrate a major decline in grasslands (−6.85%; 20.83 × 10⁶ ha) and large increases in urban areas (+43.73%; 6.87 × 10⁶ ha), farmlands (+0.84%; 1.48 × 10⁶ ha), and forests (+0.67%; 1.52 × 10⁶ ha). The total soil organic carbon pool has been reduced by approximately 11.5 Tg of carbon (TgC) year⁻¹, whereas 13.2 TgC year⁻¹ has accumulated in the biomass carbon pool because of land-use category change. Large carbon losses (approximately 101.8 TgC year⁻¹) have resulted from land management failures, including forest fires and insect pests. Overall land-use change and land management have contributed about 1.45 Pg of carbon to the total carbon released from 1990 to 2010. Our results highlight the importance of improving land-use management, especially in view of the recently proposed expansion of urban areas in China.