The purpose of this study was to examine the effect of preceptorship on On the Job Training of new nurses. The research design was a retrospective survey and one group pre-post test design. The subjects were 49 entry nurses and 49 preceptors. The data were collected from Feburary 1, 1998 to December 1, 1998. One questionnair applied in this study consisted of general characteristics, the responses of new entry nurses and their preceptors and their qualities. The other questionnair consisted of job satisfaction of new entry nurses and preceptors and their competencies. The data were analyzed for frequencies, mean score, standard deviation, t-test, and ANOVA. The results of the study were as follows: 1) Preceptees's responses were that the nurses' affiliation of unit, cooperation of other nurses, and competencies of nursing skills improved after OJT applied preceptorship. 2) Preceptors's answers were that preceptor- ship had a positive effect on their continuing education. 3) While preceptees's job satisfaction scores were high in interaction, administration, and organization, they were low in autonomy and pay. 4) Pre-competency scores were the same as post-competency scores. 5) After preceptorship, preceptors responded that their nursing skill & communication competency increased, but their nursing administration competency decreased. 6) Finally, preceptorship's other effects were as follows: 1. Checklists for preceptee education at the nursing unit were developed separately. 2. It was proved that 'preceptor interview note' was effective on manage preceptorship. 3. We obtained duty overlap periods; medical- surgical units-1 month, 5 ICU-2 months, operation room-3 months. 4. We prepared a preceptor program based on the study results.