In a T-shaped mixer, the two liquid streams in the inlet channels meet each other at the T-junction, and their liquid-liquid contacting face exhibits planar, swirling folds and the folds breaking to be chaos and turbulence, as the Reynolds number increases. The characteristic mixing scenario attracts long-time atten-tion, given these mixings are of fundamental importance in fluid physics and also have been successfully used in engineering applications. The experimental and numerical studies of flow features and mixing characteristics in T-mixers are overviewed in this manuscript. This review introduces the experimental and numerical techniques in the studies, the flow and mixing characteristics in the corresponding regimes and application examples of the T-mixers at last, aiming at introducing fundamentals to researchers with initial interests on this topic.& COPY; 2023 The Author(s). Published by Elsevier Ltd on behalf of The Chinese Society of Theoretical and Applied Mechanics. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )