Abstract: Power consumption, mixing time, velocity distribution and How patterns in agitated vessel of 0.286m in diameter with various types of helical ribbon impellers were measured with syrup, CMC solution and Boger fluid as test fluids. The effects of rheological properties of the fluids on axial velocity, tangentical velocity and radial velocity in the vessel with the presence of secondary flow were quantitatively described. It was also indicated that flow patterns of high viscoelastic fluid were quite different from those of high viscous fluid. Interpretations of power consumption and mixing time data were given on the basis of flow pattern observations.