The purpose of this study was to examine the relationship between elementary school students\' personality and parents\' rearing attitude by the sibling composition of them. It\'s specifically meant to determine the relationship of sibling composition to parents\' rearing attitude, of sibling composition to child personality and of parents\' rearing attitude to child personality. The study was carried out through review of literature and survey. The sample size of this study were 500 students randomly selected from among six graders in two different elementary schools in the city of Incheon. After a survey was conducted, the responses from 450 students were chosen for analysis. The questionaires were developed by the reasearch based on review of literature. A Parents\' Rearing Attitude scale (40 items) classified parents\' rearing attitude into four : achievement-nonachievement, openness-closure, acceptance-rejection, and autonomy-control and a Children\'s Personality scale (120 items) dealt with six personality subareas : security, activity level, dominance, sociability, considerateness and responsibility. The reliability of the scales was calculated by using Cronbach\'s lapha. The Cronbach\'s alpha coefficients were 0.72 for achievement-nonachievement, 0.73 openness-closure, 0.60 acceptance-rejection, and 0.65 autonomy-control which are subscales of the Parents\' Rearing Attitude scale. Also, each coefficient the Children\'s Personality scale was 0.77 in security, 0.75 in activity level, 0.79 in dominance, 0.79 in sociability, 0.78 in considerateness, 0.86 in responsibility. For data analysis, variance analysis was implemented to find out the relationship of sibling composition to parental rearing attitude and child personality, and correlational analysis and stepwise multiple regression procedure were employed to identify the relationship between parental rearing attitude and child personality. The findings of this study were as below: First, in conjunction with the number of siblings, the parents who had one child had a more achievement-oriented attitude, and the parents who had two or more children showed a more open, acceptive and autonomous attitude. By order of birth, the parents took a more achievement-oriented attitude toward the oldest or middle children than toward the youngest ones, and toward only children than toward the oldest ones. They showed a more open attitude toward the youngest children than toward the middle ones, and their attitude toward only children was most closed. The gender of siblings had nothing to do with parental rearing attitude. Second, as for connections between sibling composition and child personality, the children who had two siblings had a more stable personality than those who were only children or had three or more siblings. By order of birth, the oldest and youngest children had a more stable personality than those who were only children or the middle children. The oldest or only children were more considerate than the middle or youngest children. The oldest children were the best in a sense of responsibility, followed by the youngest children and only children in the order named. The middle children were most inferior in a sense of responsibility. The gender of the siblings made no significant difference to the children\'s personality. Third, regarding connections between parental rearing attitude and child personality, the children\'s security was predicted by openness-closure, acceptancerejection and achievement-nonachievement factors, and these factors made a 17.1% prediction. In particular, achievement-nonachievement factor was negatively correlated to their security. The children whose parents had an achievement-oriented attitude excelled the other children in terms of activity level, and this factor made a 8.3% prediction of the children\'s activity level. The child dominance was predicted by acceptance-rejection and achievementnonachivement factors, and these factors made a 13.8% prediction. The child sociability was predicted by achievement-nonachievement, acceptancerejection, and autonomy-control factors, and these factors made a 10.3% prediction. The child considerateness was predicted by achievement-nonachievement, acceptance-rejection and autonomy-control factors, and these factors made a 11.8% prediction. A sense of responsibility was predicted by acceptance-rejection and autonomycontrol factors, and these factors made a 11.2% prediction. The impact of sibling composition and parental rearing attitude on child personality varied from group to group.