This book has 13 chapters in total. The main contents include: hydrostatics, liquid kinematics, foundation of liquid dynamics, liquid flow pattern and head loss, orifice, nozzle outflow and pressure pipe flow, open channel constant flow, open channel unsteady flow, weir flow, gate hole outflow and tunnel culvert overflow, connection and energy dissipation of water flow downstream of the drainage building, seepage, similarity theory and dimensional analysis, hydraulic experiments, etc. This book's exposition is concise, paying attention to strengthening the theoretical foundation, focusing on cultivating students' abilities, and facilitating teaching. This book can be used as a textbook for undergraduates and junior college students majoring in water conservancy and civil engineering in colleges and universities, and can also be used as a reference for graduate students in related majors and related engineering and technical personnel.