Abstract: In recent years, medical social work, as a new field of social work, has become increasingly important in medical and health service. However, there are various ethical issues in practice. At present, domestic research mainly focuses on theoretical studies that are still explorative but not qualified for promotion, and lacks empirical studies that are rooted in practical experience. Combined with the methods of literature analysis and qualitative research, this paper examines six cancer patient cases to investigate the ethical dilemmas in practicing medical social work from two dimensions, namely the conflict of dual relations and of values. These include the conflict between keeping disease information confidential and the client's right of informed consent; discrepancy between the principle of self-determination and traditional or professional values; differences between professional value and sensitivity. Medical social workers need to have an integrated thinking and take into account professional ethics and values, role orientation, interdisciplinary cooperation and ethical decision-making steps, attach importance to informed consent and dual relations, and make reasonable ethical decisions.

Key words: medical social work, ethical dilemma, cancer patients