Abstract The size and attribution of the regional net carbon flux from land-use change (LUC) activities ( E LUC ) are often highly debated, especially in regions such as China, which has experienced decades-long extensive reforestation activities. Here, using a LUC dataset incorporating remote-sensing and national forest inventory data with two modelling approaches, we show that E LUC in China shifted from a carbon source to a sink in the 1990s, contributing to a net cumulative CO 2 removal of 2.0 Pg C during 1981–2020. From 2001 to 2020, the average E LUC was −0.14 Pg C yr −1 , accounting for over one-third of the national land carbon sinks. Forest-related LUC activities contributed greatly to national carbon fluxes, while non-forest-related activities played a dominant role in certain areas. Our findings suggest that the carbon sinks from LUC activities in China may be largely underestimated in global assessments, underscoring the need to develop region-specific modelling for evaluation and potential regulation. This is a preview of subscription content, access via your institution Access options Access through your institution Access Nature and 54 other Nature Portfolio journals Get Nature+, our best-value online-access subscription $29.99 / 30 days cancel any time Learn more Subscribe to this journal Receive 12 print issues and online access $209.00 per year only $17.42 per issue Learn more Buy this article Purchase on SpringerLink Instant access to full article PDF Prices may be subject to local taxes which are calculated during checkout Additional access options: Log in Learn about institutional subscriptions Read our FAQs Contact customer support Data availability The primary results presented in the study are available via Figshare at https://doi.org/10.6084/m9.figshare.28252124 (ref. 50 ). The original LUCD dataset created by ref. 22 is available at https://doi.org/10.12199/nesdc.ecodb.rs.2023.015 . The IBIS land carbon sinks estimated by ref. 24 […]