We studied medicinal theory on processing drugs of Wang-Ang. Wang-Ang used various methods of medicinal processing. He used such as soaking(浸), maceration(泡), washing(洗), elutriation(淘), mixing together(拌), refining powder with water(水飛) and floating(水漂) in medicinal processing with water. He used such as making hot(?), roasting in ashes(?), stir-frying with liquid(炙), parching(炒), heating(燒), baking(焙), stirring-baking(?) and distilling(煉) in medicinal processing with fire. He used such as steaming(蒸), boiling(煮), making hot and soaking(??) in medicinal processing with water and fire. And He used such as cooking(熟), making drugs into gelatin(制膠), making drugs into frostlike powder(制霜法), making drugs into bead(制珠), fermentation(生衣) and compound medicinal processing(複制法).