In order to the comparative morphological study of the non-ciliated and ciliated epithelial cells, and to elucidate the process of degeneration of non-ciliated epithelial cell of the ductus epididymidis, Korean striped field mouse, Apodemus agrarius coreae was examined with light and transmission electron microscopes. The morphological characteristics of non-ciliated epithelial cell, the cell types of the caput epididymidis (Cp), corpus epididymidis (Cr) and cauda epididymidis (Cu) were long-columnar, short-columnar and short-cuboudal, respectively. The mitochondria and rough endoplasmic reticulum tended to be broken as they immigrated from Cp to the Cu. The Golgi acted vigorously at the Cp, but the Golgi was inactive in Cr and Cu. The secretory vesicles and lysosomes were increased gradually from Cp to the Cu. The process of degeneration of the non-ciliated epithelial cells observed in the Cp, Cr and Cu epididymidis. The increase of the non-ciliated epithelial cells, and its degeneration were observed more often from Cp to the Cu. The morphological characteristics of the ciliated epithelial cells, the cell types of the Cp, Cr and Cu were long-columnar, short-columnar and short-cuboudal, respecptively like the non-ciliated epithelial cells. The stereocilia was long and slender at the Cp and Cr, while Cu was very short. The pinocytotic vesicles and absorptive vesicles were increased from the Cp to the Cu. Numerous disintergrated products was existed at the Cr including the Cp, but Cu were not observed. A significant amount of lysosomes existed at the Cp and Cr epithelial cells, but they were not observed in Cu epithelial cells.