Oil bodies (OBs), one of the major components of soymilk, are very important for the properties of soymilk and its related products. In this study, the properties and the related protein behaviors of OBs in the soymilk preparation were systematically examined. Raw soymilk OBs could keep their natural integrities after grinding, and they were bound by many soybean proteins (mainly β-conglycinin, glycinin, and Gly m Bd 30K) that could be removed by pH 11.0 washing. Heated soymilk OBs, including heat-induced coalesced OBs (>1 μm) and modified OBs (around 400 nm), were strongly bound by β-conglycinin and glycinin that even could not be removed by pH 11.0 washing. The oleosins (24 kDa, P29530 and P29531; 18 kDa, C3VHQ8) of raw soymilk OBs were hydrolyzed to 16 kDa polypeptides (on SDS–PAGE gel) when exposed to room temperature, while immediately heating, the raw soymilk could prevent the oleosin hydrolysis. Then, the isolated raw and heated soymilk OBs revealed different dispersion stabilities as a function of pH. At last, tofu curds were made from two reconstituted soymilks containing non-lipid soymilk and raw or heated soymilk OBs (pH 11.0 isolation), and one trend was found that tofu curds containing heated soymilk OBs had lower breaking stress and Young’s modulus than those containing raw soymilk OBs. It is considered that this study is meaningful for designing new strategies to improve the qualities of soymilk and its related products.