This paper describes a method for using the S/360 CSMP digital simulation language to implement the computer simulation of a nonlinear model of a multi component distillation column. The method makes it unnecessary to linearize the nonlinear vapor-liquid equilibrium relationship by employing a “pseudo- linearization” approach to this nonlinearity. This approach yields a computer simulation capable of operating over the complete range of the original model. The method is applied to a model of a ternary (benzene-toluene-xylene) distillation column which consists of 11 plates, a condenser, and a reboiler. The simulation results are then compared to known experimental results as a means of validating the simulation. Except for initial transients, the two sets of results are in close agreement, which sug gests that the pseudo-linearization technique pro duces a satisfactory model of the distillation column.