A computer simulation of biochemical process was carried out using Macintosh-based BioDesignerTM developed at Bioprocess and Engineering Center(BPEC) of MIT. Based on the assumptions and flask culture experiments, a porcine growth hormone (PGH, Porcine Somatotropin) production process was simulated by a two-stage continuous culture. The economical and sensitivity analyses were evaluated for the scale-up production of PGH. A high return on investment (ROI, 104%/year) suggested that the process be profitable. However, sensitivity analysis indicated that ROI was dependent on the yield of PGH, selling price, dose and the achievement of projected market penetration.