Based on enlarged fishway construction of Dayuandu navigation & hydropower complex in Xiangjiang River,we discuss several design problems that should be considered in enlarged fishway construction on constructing or constructed navigation & hydropower complex.The thoughts and methods to determine the fish migrating objects and time,the operation water levels,elevations of fishway inlet and outlet,the fishway design velocity,the fishway structure type,and the layout of fishway entrance and outlet have been analyzed emphatically.Analyses show that four famous domestic fishes are the mainly fish migrating objects in Xiangjiang river;the design velocity of fishway is 0.2~1.3 ms,which is more favorable for fish migrating;the key to the fishway design is the layout of the inlet,thus,proper consideration of attracting fish can enhance the effect of fish migrating;the fishway project should be considered in conjunction with enlarged lock construction.This paper summarizes the experience of fishway design under limited factors such as actual topography and existing buildings,which can have some reference significance for similar projects.