<p>Provided is a biopolymer originating in Eucommia ulmoides which is obtained by a step of biologically decaying E. ulmoides to give a degradation product of E. ulmoides and a step of washing this degradation product of E. ulmoides. The biopolymer, which is obtained by such a convenient method as described above, contains trans-isoprenoids as the major component and has a relatively high molecular weight. Therefore, it has characteristics as a solid elastomer and is useful as an industrial material.</p>
