The residual sulfur dioxide in the five herbal medicines dried with burning bituminous coal for 9 hours showed from 339 (Glycyrrhizae Radix) to 1,138 mg/kg (Zingiberis Rhizoma) measured right after drying. The residual sulfur dioxide, from 70.1 to 95.5%, was remained in the above five matrices even after 30 days passed. The marker components concentration in above five herbal medicines like glycyrrhizic acid, betaine et al., were almost same after drying in oven and with burning bituminous coal.