Abstract
The purpose of this study is to find out the characteristics of assertion of nurses and the related factor by means of The Nurse' Assertion Inventory which was developed newly. Subjects were 674 nurses which participated in the assertion training in 4 area 5 place. The following things became clear as the characteristics of the assertion of nurses as a result of the investigation. Generally subjects were assertive, and non-assertive toward doctor and boss, difficult to express assertively toward colleagues. In addition, as much as an age was old and the years of clinical experience were long, the nurses express themselves assertively or aggressively. It was suggested that it was necessary to develop an assertion training program for nurses taking into consideration of years of clinical experience and cultural background.