Construction of dam and barrier in stream cut off the migartion passage of varieties of fishes and aquatic livs. Different types of fishways were accommodated to those dam and barrier, however less were successfully adopted by fish and aquatic species. It is presumed that flow conditions and entrance environment of those fishway are not suitable and adequate. The author carried out hydraulic experiments with various shapes and sizes of appurtenance in fishway and observed different flow phenomena. Hydraulic experiments are also conducted in sloping channel to compare them with fishway. This book will help to understand the flow scenarios to improve design of pool-and-weir fishway.