Relationship between detection geometry and spectropolarimetric bidirectional reflectance distribution function for soil background was analyzed in detail. The modeling of spectropolarimetric bidirectional reflectance distribution function was proposed based on LS-SVM, aiming to extend the value of measured spectropolarimetric bidirectional reflectance distribution function with limited geometry to whole hemi-sphere space. Results show that the predicted value and experimental value are close and meet the need of correction.