The purpose of this study is to determine the optimum conditions of the extrusion process. Extrusion tube which is the main material of the intravenous set is produced in the extrusion process. In this paper, design of experiments is used to derive the regression model of the tensile strength and the transmittance rate for extrusion tube. The output variables were selected as tensile strength and transmittance rate, the input variables were selected as cylinder temperature, die temperature, lip die temperature and work room temperature. The experiments were conducted as full factorial experiments by 2-level, 4-factors. Through the design of experiments, we have analyzed the main effects and interaction effects of the input variables on the tensile strength and the transmittance rate of the extrusion tube and derived a predictive model. The result was that the tensile strength under the optimal condition was improved by 15% compared to those before improvement.