Manufacturers widely apply the process of blanching soybeans to eliminate the beany off-flavor in the preparation of soymilk. However, the state of soy protein and the rheological properties of blanched soymilk are still unclear. In this study, the distribution of lipid and protein was analyzed by the ultracentrifugation method which separates different fractions on the basis of their particles size. The blanching process has changed the aggregation mechanism of particles in the traditional soymilk, thus entrapping parts of the oil bodies to particulate proteins. This study provides excellent references for technology innovations on manufacture and improvement of soymilk quality. However, the combination mechanism of oil bodies and particulate proteins and the influences on their rheological properties still needs to be further studied.