Objective: To study the technological parameters of the extraction process of volatile oil in eucalyptus leaves by supercritical CO_2 technology. Methods: On the basis of one-factor-at-a-time-technique test, the Box-Behnken central-composite designed response surface with 3 factors and 3 levels was adopted. A second order quadratic equation for volatile oil from eucalyptus leaves was built. The response surface methodology( SM) with three factors and three levels was used to optimize extraction process by s...