Several groynes were constructed to protect the banks of Japanese rivers. To investigate the effects of groynes on the Shigenobu River in Japan, a field investigation was conducted to measure the sizes of groynes and stones on the surface as well as the bed morphology around the groynes. In addition, particle tracking velocimetry and numerical analyses of the three-dimensional flow and bed variation around the groynes were conducted. Distributions of mean velocity and Reynolds stress, and the bed variation around successive groynes were affected by the arrangement of groynes.