One of the important themes of nursing science is now what is the methodological principle adequate for the inquiry of nursing knowledge and how the principle should be investigated. Nursing science as a systematic science requires a body of nursing knowledge which should be demonstrated and developed through nursing studies. The present task of nursing science research is to develop a body of nursing knowledge through scientific research and analysis and establish nursing science a systematic science. The purpose of nursing science is to help a human being. The purpose of nursing science is to help a human being. The concrete program for accomplishing it is based on the comprehension of the philosophical characteristics involved on nursing science and the general considerations on the human beings and the deep understanding of the human experience. This article discusses the relation between science and philosophy, the necessity of a philosophical approach to nursing, the philosophical elements included in nursing, Husserl`s phenomenology, the philosophy of Edith Stein, Merleau-Ponty and Dilthey, and Van Manen`s phenomenological research metholology. Nursing is a profession practiced on the basis of humanism. And the basic philosophy focused on freedom and individuality underlies human behavior. A human being as aopen system possessive of growth ability determines his own reality in interaction with environment. Man is endowed with essential features of interpreting his own experience and giving a meaning. The norm of phenomenology is that one should require nothing except for what one can essentially penetrate in consciousness it-self, namely pure immanence. In other words, whatever is originally provided in one`s intuition should be accepted as it is. Thus phenomenological description describes what reveals itself and what is given just as it is. Phenomenology is a open research methodology that allows various interpretations. It attempts to get rid of all prejudices on the world and reveal the world of concreteness as it is. A human being is always within the world, lives a life through the world and knows himself in the world. The phenomenological Research Methodology signifies that nursing science should take its starting point in general knowledge on nursing phenomenon and regard the object of nursing, namely man`s health problem as part of life experience. Phenomenology is a qualitative research methodology proper to professional nursing research. Because it tries to provide a research approach to man`s lived experience and describe the significance of a human being who concerns himself in experience and grasp the interdependence and interrelation between nursing science and humanism. The phenomenological research methodology aims at understanding man`s experience. Phenomenological methodology is necessary, since the research methodology of natural science is inadequate to comprehend man`s lived experience. Quantitative research methodology and qualitative research methodology have their own merit and limit respectively. By properly applying quantitative methodology on the basis of qualitative methodology, one should generalize the forms of explanation and prediction and supply operation and regulation, understanding and selection.