Background: China has experienced dramatic social changes in the last three decades. This study aimed to investigate socio-economic factors related to suicide rates in China from 1990 to 2015, and examine how the impacts of these factors on suicide rates changed over time. Methods: Suicide rates in 31 provinces in mainland China between 1990 and 2015 were obtained from the Global Burden of Disease (GBD) Study 2019. Temporal-spatial modelling was applied to assess the effects of GDP per capita, urbanization, migration, employment, divorce, proportions of children and older adults on provincial overall, male and female suicide rates. Findings: The overall suicide rate in China declined from 18·1 /100,000 in 1990 to 8·6 /100,000 in 2015, with considerable spatial variation in the magnitude of decline across provinces. The protective effects of increasing in GDP per capita, and urbanization, on provincial suicide rate were strong in 1990 (log GDP: -3·56 [95% CI: -6·15, -0·96], urbanisation: -0·07 [-0·14, -0·01]), however these effects were negligible by 2015. The association between employment and suicide rates has shifted from positive to negative over the study period, while migration remained a constant risk factor for high suicide rates (0·04 [0.00, 0·09]). Interpretation: This study highlighted the dynamic effects of economic and social factors on suicide rates in the context of transforming China. To maintain further reductions in suicide rates cannot rely simply on improving people's materialistic and economic conditions. A more holistic approach to improve overall population well-being is needed. Funding: Humanities and Social Sciences Prestigious Fellowship (37000320) and the General Research Fund (17611619) at the University of Hong Kong.