This paper studies the temporal and spatial evolution of the flow structure of world coal resources in 1990-2016 and explores reasons of the evolution. From the perspective of the "resources field" theory, the coal flow from the sources of the flow field with high-potential to the destinations of the flow field with low-potential through intensive shipping routes. In 2016, the number of coal shipping routes increased significantly compared with 1990, and the transport volumes also increased significantly. The main factors that motivate coal resource flowing around the world are resource spatial distributions, supply-demand matching degrees, space distances, market factors and national policies etc. In the complex supply-demand structure of coal resources, establishing good rules and order for international coal trade and enhancing the reliability and smoothness of maritime transportation corridors is very important for the maintenance of world economic security. (C) 2018 Elsevier Ltd. All rights reserved.