There was necessary to study that the magnetic application is effective to menstrual pain based on rogers theory about energy exchange. The purpose of this study was to examine the effectiveness of magnetic application in primary dysmenorrhea and so this study provide the basic information about nursing intervention of pain relief. The data was gathered from 23 student nurses at S University during the period of June 1. 1992 to October 5. 1992. This study was designed with control group pretest-posttest design to examine the effectiveness of magnetic application in primary dysmenorrhea. The subjects were experiencing self-reported dysmenorrhea above 5 scores measured by GRS during menstruation. The subjects were assigned randomly to one of two groups: 1) an experimental group (n = 11) that applied magnet (800-1299 gauss) or 2) a control group (n = 12) that applied nonmagnet. Both groups' pain level was assessed using the GRS (Graphic Rating Scale) which was developed by Scott and Huskisson (1976), and the ALPRSR (Adjective Labor Pain Rating Scale Rank) and ALPRSS (Adjective Labor Pain Rating Scale Score) which was developed by Park and Hur (1984). The pain level of experimental group was measured first 9 a.m. after beginning of dysmenorrhea, Md (3 hours after applied magnet) and 3 p.m. (3 hours after detached magnet). The pain level of control group was measured first 9 a.m. after beginning of dysmenorrhea, MD (3 hours after applied nonmagnet) and 3 p.m. (3 hours after detached nonmagnet). The both group applied magnet or nonmagnet on the suprapubic area, the bilateral lumbar 3 and above 4FB of the medial malleolus of tibial bilaterally. The research data was analyzed by SPSS/PC+. The results of this study were as follows: 1) 3 hours after applying magnet or nonmagnet (MD), The GRS mean rank was significant difference statistically (p = 0.0001). 2) 3 hours after applying magnet or nonmagnet (MD), the ALPRSR mean rank was significant difference statistically (p = 0.0106). 3) 3 hours after applying magnet or nonmagnet (MD), The ALPRSS mean rank was significant difference statistically (p = 0.0086). 4) 3 hours after detached magnet or nonmagnet (3 p.m.), the GRS mean rank was significant difference statistically (p = 0.0070). 5) 3 hours after detached magnet or nonmagnet (3 p.m.), the ALPRSR mean rank was significant difference statistically (p = 0.0317). 6) 3 hours after detached magnet or nonmagnet (3 p.m.), The ALPRSS mean rank was significant difference statistically (p = 0.0374).(ABSTRACT TRUNCATED AT 400 WORDS)