Abstract: Oblique practical weirs are often the designers’ choice for mid- and small-scale water conservancy projects that are limited by natural riverbed boundary conditions, but their discharge capacity is still a technical issue. This paper examines the characteristics of flows around oblique practical weirs, analyses discharge coefficient and its influencing factors, and develops a discharge calculation method, based on 20 sets of experimental tests covering four oblique angles (0°, 30°, 45°, and 60°) and five discharges. Results show that in comparison to the normal weir in a channel with the same width, these weirs have larger approaching velocities and generally create no circulation zone, but in front of them the mainstreams are deflected. An oblique weir is more applicable when the water head is low, while under high water heads its discharge capacity still exceeds the normal weir. We work out a formula for calculating the discharge of oblique practical weirs and show its error in the range of 4.63% relative to the measurements, meeting the need of most engineering designs.