$Yongkaksan^{circledR}$ is a powdered crude drug which is used to treat cough and recommended it as an expectorant. It is composed of Platycodi Radix (11.7 mg), Senegae Radix(0.5 mg), Armeniacae Semen(0.83 mg) and Glycyrrhizae Radix(8.3 mg). For the identification of individual ingredients in such powdery mixtures, microscopic method may be considered to be efficacious due to requirement of a small amount of specimens. In this paper, effectiveness of this method will be exemplified by the identification of the ingredients in $Yongkaksan^{circledR}$ which contains 4 powdered crude drug ingredients.