Distillation experiments for binary system ethylformate-acetone were carried out using a 15cm I.D. and 135cm height packed column under total reflux condition. Comparing experimental and calculated concentrations profiles of liquid phase, distances between two adjacent mixing points of 10.1, 15.18 and 19.40mm ceramic Rasching rings were determined. The distance was increased according to the increasing dimension of packings and an empiri-cal correlation between them was proposed. The experimental results also convinced of the utility of the model column which simulates the flow phenomena in an industrial parcked column, proposed in previous article, for phenom-enological study of mass transfer.