The purpose of this study was to define the effects of nursery teachers` and infants` temperaments on their attachment stability. The subjects of this study were as follows: 32y 4 nursery teachers and 324 infants between the ages of seven months to two years, drawn from forty daycare centers located in Jeollabuk-do. In terms of research instruments for the study of nursery teachers, DOTS-R (Revised Dimensions of Temperament Survey) for adults (Windle and Lerner, 1986; modified by Kim, 1993) was applied. For the study of infants, TTQ (Toddler Temperament Questionnaire) (Fullard, Mcdevitt & Carey, 1984; modified by Choi (1991) was applied. The measurement of attachment, based on attachment Q-sort (Waters & Deane, 1985, modified by Cho, 2007), was applied. The results were as follows: First, attachment is more stable when the nursery teachers have better mood and higher accessible but lower flexibility. Second, infants with higher accessibility and adaptability have a higher stability of attachment with the nursing teachers, while infants with lower response intensity have a higher stability of attachment.