A mathematical model was developed to quantitatively analyze the rate of soybean oil extraction at varying extrusion parameters including material moisture, expanding temperature, the die length, the length of section δ and the rotate speed of screw. Kinetic parameters were estimated and correlated with the oil concentration of extrusion soybean products at different extraction time. The kinetic model identified microstructure development upon varying extrusion conditions. By analyzing characteristics of soybean fat globules for different extrusion masses, it showed that positive correlation between the size of fat globules and the diffusivity index. To enhance oil availability and extractability, the quantity models were developed to describe the relations of varying extrusion parameters and extraction time when the ratio of residual oil of soybean meals was 1%, it was used to obtain optimal extraction time for different extrusion conditions. Observed experimental oil extraction data fitted well with the developed soybean mathematical models.