The carbon stock in timber has been included in the carbon removal category of the national greenhouse gas inventory, and the measurement of a nation's timber carbon stock determines the allocation of its responsibility for reducing carbon emissions in future climate change negotiations. However, the leakage of global timber carbon stock is prominent, calling for unveiling the flow patterns of global trade-embodied timber carbon stock to scientifically allocate the contributions of cooperative emission reduction among nations. This study employed the multi-regional input-output model based on the Eora database to calculate the volume of timber carbon stock and analysed the spatial and temporal characteristics of 190 nations between 1990 and 2015 from the perspectives of production, consumption, and trade. Furthermore, it identified the directions of the timber carbon stock flow of critical nations. Based on the principle of “common but differentiated responsibilities”, we explored the allocation of timber carbon stock between suppliers and consumers. The results of this study show that developed nations consume a high volume of the timber carbon stock from developing and undeveloped economies through international trade. The top 10 nations in production- and consumption-based timber carbon stock are the main sources of global timber carbon stock, with average contributions of 59.1% and 62.2%, respectively. The research findings expand the scope of carbon stock research to timber products, contributing to advancing global climate negotiations and cooperative carbon emission reduction.