Nowadays a contact between Buddhism and Christianity is necessary. The dialogue between Buddhism and Christianity leads one to realize the richness of one’s religious belief and to be aware of one’s religious tolerance, and then to respect each individual’s religious experience. This thesis, therefore, will explore the meaning and the value of religious lives of Catholic sisters and of Buddhist nuns and their differences. On the basis of examining my own belief and reflecting on Catholic and Buddhist traditions, this study aims to help us to live a fuller religious life which can correspond to the need of our time, lead us to peace and the source of life, and make the society more harmonious. This thesis is a comparison and contrast between the religious lives of Catholic sisters and of Buddhist nuns. The purgative way, the illuminative way, and the unitive way are used to signal Catholic sisters’ vows of poverty, chastity, and obedience. In their spiritual development, Catholic sisters go through the purgative way, the illuminative way and the unitive way until finally to be with God. The Buddhist nuns, on the other hand, focus their religious life on discipline, meditation, and wisdom, the classic three stages of development in Buddhist spiritual life. Through the comparison and contrast, we can find the religious lives of Catholic sisters and of Buddhist nuns seem to be similar but in fact are quite different. On certain level they may enlighten each other in living the life of self-sacrifice. Nevertheless, because of the differences in their understanding of Divinity and in their values, their essential differences are not negligible at all.