One important area for our observation of past women’s social life and status is the extent to which they were required to follow chastity rule and its relevant boundaries. There have been many research reports on ancient Korean politics, economy and religion that tangentially touched on this issue, and this provides the impetus for the current paper to focus on ancient Korean women’s ideas of chastity. The major sources of information are two ancient tests: Samkuksaki (《三國史記》) and Samkukyusa(《三國遺事》). Our analyses focus on the following issues: whether women preserve virginity before marriage; whether women remain chaste toward their husbands after marriage; and, lastly, the extent to which and the difficulty involved for divorced women who wanted to remarry. Preliminary findings indicate that women during the Shilla period generally observe the following rules: no chastity requirement before marriage; post-marital chastity is universally followed; and no requirement that women should follow one-husband-only rule. During the Korguyo period, because it followed the “levirate” practice commonly seen among nomadic peoples, women enjoyed most pre-martial sexual freedom. Besides the rule of conjugal chastity, women did not have to follow one-husband-only rule. The Baekje’s society only prescribed that women should maintain chaste; they would be punished otherwise.