Subjects for the study were 185 five-year-old children (105 boys and 80 girls) attending nine classes of public kindergartens in Icheon, Gyeonggi. Results of the study were as follows: First, percentages of easy, slow, and difficult temperament groups were 14.1%, 66.5%, and 19.5%, which were perceived by teachers. Easy temperament group had more girls than boys, whereas difficult temperament group had more boys than girls. Slow temperament group had similar numbers of boys and girls. Second, teachers perceived that their relationships with young children were rather harmonious and positive. However, they perceived their relationships to be changed by young children’s sex. Regarding the differences in sub-scales for teacher-child relationships by sex, teachers perceived conflict to be higher with boys than girls, while they perceived closeness and dependency to be higher to or with girls than boys. Third, teachers’ relationships with easy children were perceived to be medium or low conflict, average closeness, and medium or low dependency. These perceptions showed no differences by sex. Teachers’ relationships with slow children were perceived to be medium conflict and high or medium closeness and dependency. These perceptions showed differences by sex. Specifically, teachers perceived similar conflicts with boys and girls, higher closeness to girls than boys, and higher dependency with boys than girls. Teachers’ relationships with difficult children were perceived to be high or medium conflict and medium or low closeness and dependency. These perceptions on conflicting relationships showed differences by sex. In specific, teachers perceived similar conflicts with boys and girls but experienced higher conflict with boys than girls. No differences by sex were found in closeness and dependent dependency relationships.