The total withdrawal operation is an inevitable section in cyclic total reflux batch distillation. In the operation, an interesting phenomenon "overhead concentration platform" (OCP) appears, which is defined as a period of time with high overhead concentrations when the operation is changed from total reflux to total withdrawal. The OCP phenomenon and its influential factors, such as the theoretical stage number, feed concentration, and feed composition, are examined by simulations and experiments. The experimental equipment is a column with random packings. It is shown that the number of theoretical stages influences the OCP more significantly than the other factors.