Taking Laokou junction for example,we study the flow patterns in the upper & downstream entrance area of approach channel on S-shaped curved river by physical model test.The overall model test of Laokou junction and the self-propelled ship model test with both scales 1:100 are adopted to choose some comprehensive measures to improve the flow patterns near the upper approach channel and downstream approach channel.The study results show that,some modification facilities such as partition walls with hollow base,diversion pier,slope excavation,back slope,submerged dike and adjusting bank line,are all used in the modification scheme and get great effect,which provide a basis for the optimized arrangement and navigation condition design.