Context The effects of no-tillage (NT) on soil organic C (SOC) and rice yield in lowland soils are poorly understood in subtropical ecosystems. Aims In a long-term (24years) field experiment, we assessed the effect of NT on SOC stocks in labile (>53μm, particulate) and stable ( Methods Soil from eight different layers down to 40cm under each tillage system was sampled in a field experiment, and additional soil samples were obtained from an adjacent area under native grassland (NG) as reference for SOC stocks. Key results While the PG and CT systems maintained similar SOC stocks as the NG soil, NT increased SOC stocks at an annual rate of 0.41Mgha−1 in relation to the traditional CT soil. Rice grain yield increased twice over the 24-year period, amounting to 12Mgha−1 in the last crop season. Despite lower yield in NT system in most crop seasons, a slight effect on yield stability and profitability ( Conclusions Based on our findings, NT promotes C accumulation in subtropical paddy rice soils. Implications There is a beneficial effect of NT on rice yield stability and profitability in the long term.