Theoretical frameworks and measurements for interpersonal emotion regulation in adults are well-established. However, the understanding of interpersonal emotion regulation in young children remains unclear, and no measurement tools exist for their specific strategies. This study aimed to develop a questionnaire for assessing interpersonal emotion regulation in children aged 3-6. Through a series of four studies, we developed the Children’s Interpersonal Emotion Regulation Scale (CIERS). The final scale comprises 21 items across five factors: Extrinsic Emotion Improvement, Receiving Comfort from Others, Positive Emotion Sharing, Extrinsic Emotion Worsening, and Self-Soothing. The scale demonstrates excellent psychometric properties. Implications for future research are discussed. Moreover, no gender and age differences were found in each IER dimension. This research contributes to the broader emotion regulation literature by elucidating IER strategies in young children.