The characteristics of turbulent flow and mass transfer in divergent channels of rectangular section were experimentally investigated and the typical effects of main flow and the secondary flow on mass transfer were also discussed. Sherwood number Shx1 could successfully be expressed by Reynolds number Rex1 and acceleration parameter K. Sherwood numbers S__(hx1) in the entrance region of concentration were proportional to R__(ex1)0.83 for any divergent angle, which changed more intensively than R__(ex1)0.8 for the straight channel. The velocity profiles above the axis of divergent channels were recognized as a composite structure consisting of those in the inner and outer layers, but it was difficult to predict the velocity profiles below the axis by those of the plane jet.