Four external and 27 cranial characters of Korean field mice (Apodemus peninsuluek from nine localities in eastern Asia, representing ave subspecies, were analyzed by multivariate statistical methods. Three forms were recognized: a large-size form from Korea (subspecies peninsulael, southern Manchuria (praeto4, and northern Manchuria (majofi a middle-size form from urestern Siberia (tschergal and southuvestern China (sowerbyi); a small-size form from northeastern China (sowerbyi). It is also revealed that variations among the three forms are clinal rind circular. It is confirmed that Apodemus peninsuloe could be classified into two subspecies (peninsulae and sowerbyl) within the distribution range in the continent of Asia, as noted tv Corbel (1978). However, it is found that subspecies peninsulae includes praetor and moior and that subspecies sowerbyi includes tscherga, indicating that subspecies tscherga is not the synonym of subspecies peninsulae, but that of subspecies sowerbyi.