AKUTAGAWARYUUNOSUKE is the representative writer of new-thought group, his works are not only with romanticism, but also contain realism. He claimed that works should analyze the reality rationally and reflect the reality with art. AKUTAGAWARYUUNOSUKE left us with a good short story more than 200 articles in his 12 years writing career. He is called a genius and mavericks. as a representative writer of new-thought group, he created their own stories with sharp eyes and calm analysis, reflecting the humanbeings full complexity of ideology and explore the good and evil, which has profound practical significance.According to the deep analysis of“RASYOUMON”and comparison of the concept of good and evil reflected from his work and the Japanese view of good and evil itself, this thesis finally explores the unique formation elements of the concept of good and evil reflected from his work.Born in the era of instability and unrest AKUTAGAWARYUUNOSUKE has experienced a series of unfortunate events in his life, and realized the ugly of human nature and hard life. So his works are mostly full of the exaggerated description of human nature and society ugly. No matter how, the“evil" described by AKUTAGAWARYUUNOSUKE is not his original praise thing. According to the description for the ugly society and preposterous, AKUTAGAWARYUUNOSUKE showed the endless wild tenacious vitality from the ordinary people when they face the harsh reality and his admiration of human values and human warmth. No matter how, on the searching road for reality and the life ,AKUTAGAWARYUUNOSUKE felt sick of ugly society and the lives full of selfish desire and aversion. In his view, the good has became fewer and fewer and the power of the good has got weaker and weaker, while the evil forces has been growing. Therefore, the rare good is particularlyvalued by AKUTAGAWARYUUNOSUKE, even though a little good things he is also willing to capture and reflect them in his works. AKUTAGAWARYUUNOSUKE has been exposing the "evil" in his entire life while he desired the good things from his heart. When the ideal can not be achieved in reality, the writer has reached the pursuit of the absolute good through his death. The good and evil is the eternal theme of AKUTAGAWARYUUNOSUKE’s literary. The unique life experience and influence of the times has made him his unique views on the good and evil. AKUTAGAWARYUUNOSUKE hates the "evil", while has cherished vision of the "good" , while the "evil" things are far more than the "good" things in the reality, the writer exposes the evil through creative activities and superb skills, but his inner heart has been retained the persuit of the "good". This thesis, through comparing this tangled, unique concept of good and evil to the concept of good and evil of ordinary people in Japan, summed up this unique form factors of the good and evil. Hope this thesis can make a little modest for our understanding of AKUTAGAWARYUUNOSUKE’s literary and the research of human nature.