This study aims to clarify the significance of a principle-based approach to confronting moral dilemmas in clinical ethics by examining the functions of ethical principles in the practice of clinical ethics. The way of discussions that relies on ethical principles in some aspects has become very common in ethics or philosophy dealing with morality, as well as in bioethics. However, one distinctive facet of a principle-based approach to biomedical ethics, without relying on any one established ethical theory, is the proposal and defense of a set of ethical principles as a shared framework for identifying and analyzing ethical issues in biomedicine as well as guiding our action. We find that principle-based approach is the least sharable framework wherein people with diverse views can collaborate with each other in addressing common biomedical ethics challenges. However, this approach has been criticized for a number of reasons. This study focuses on one particular criticism that principle-based approaches cannot give any guide to moral dilemmas （Clouser and Gert 1990）.This point seems critical for principle-based approaches because the basic role of ethics or ethical approaches is to guide our actions. Many ethical issues in biomedical ethics, such as euthanasia or abortion, are usually analyzed as moral dilemmas derived from a conflict between principles. If a principle-based approach could not adequately address these dilemmas, it follows that it cannot fulfill the basic role of an ethical approach. However, at least in Japan, this approach has been accepted in clinical ethics practice, where the primary aim is to guide practical judgment for ethical issues in each particular case. This study attempts to advocate a principle-based approach by demonstrating that it can have profound clinical significance in not trying to explain associations between principles.