Based on gazettes issued by the concerned agencies of United Nations and recent science research situations in all over the world, the hot research topics were sorted out from recent technology field of hydrology, such as surface water, groundwater, water quality, water resources system, atmosphere-soil-vegetation, continental erosion, snow and ice, remote sensing, tracers and etc.. This reflects the current international research and development trend in hydrology to a certain extent. It will be a valuable reference for Chinese hydrologists.