Basic 7S globulin (Bg7S) is expressed by soybeans in response to biotic or abiotic stress. Bg7S is capable of binding to a 4 kDa protein which is supposedly involved in cell proliferation. Bg7S is widely found not only in legumes, but also in other plants; however, its function is still unclear. Here, Bg7S was successfully crystallized. Orthorhombic and monoclinic crystals of Bg7S were obtained under different conditions and belonged to space groups P2(1)2(1)2, with unit-cell parameters a = 111.9, b = 130.1, c = 287.8 angstrom, and P2(1), with unit-cell parameters a = 85.3, b = 137.6, c = 162.1 angstrom, beta = 91.2 degrees, respectively.