For the first time, polybutadiene is separated according to microstructure using solvent gradient interaction chromatography (SGIC). Superior separation of polybutadienes having different microstructures is obtained on a silica-based reversed stationary phase and a mobile phase of acetone-hexane. This SGIC system enables the baseline separation of 1,2-polybutadienes and 1,4-polybutadienes even in cases where the samples have similar molar masses. 2D liquid chromatography is performed with the SGIC method separating according to microstructure in the first dimension coupled to size exclusion chromatography separating according to molar mass in the second dimension, thus providing comprehensive information on both microstructure and molar mass.