Objective: This study examines the effects of biological characteristics such as gender, environmental characteristics, birth order, and mothers' warm parenting behavior on temperament type after categorizing the temperament of infants aged 1-3. Methods: The subjects of this study were infants aged 1-3 (1,377), and the 3-5th data of the Korean Children's Panel were used. Both temperament and mother's warm parenting behavior were measured by the mother in reporting method. Results: All infants aged 1-3 were classified into the same Shy sensitive type, Easy type, and Active type for each age. As a result of examining the influencing factors on temperament type, in the case of gender, boys aged 2-3 years were significantly more likely to belong to the active type than girls to be shy sensitive type. The higher the mother's warm parenting behavior, the higher the probability that all 1-3 years old were more likely to belong to the Active type than the Shy sensitive or Easy type. Conclusions: These results raise the need to reconsider the perception of temperament stability in infants and emphasize the importance of temperament goodness of fit in infants, suggesting that infants can grow in a more positive direction through positive efforts by mothers