To analyze the effect of the maldistribution of vapor and liquid flows among tube units of an internally heat-integrated distillation column (HIDiC) on its separation performance, a simulator was developed with all equilibrium stage model. The simulation study indicated that the maldistribution of vapor and liquid flows among, tube units would influence the top product specification. From the simulation results, the acceptable difference between the maximum and the minimum liquid flow rates was determined to be less than 3%. The design strategy for the high performance liquid distributor for the pilot-scale HIDiC with seven tube units was discussed. The distribution system developed was validated by experiments. Furthermore, the distributor was applied to the pilot HIDiC. Since there is no temperature distribution between tube units, the distributor seems to achieve a maldistribution rate of less than 2.5%.