Purpose: This study examined the development and validation of the Effectiveness Scale of Child Familial Influencing Behavior. This measurement is constructed to evaluate the effectiveness of child familial influencing behaviors within three-generational relationships. Methods: The effectiveness of child familial influencing behaviors was rated by two informants (parent and grandparent) on 601 children from Grade 1 to Grade 3 in China. Results: The Effectiveness Scale of Child Familial Influencing Behavior consisted of three factors with 12 indicators related to highly influential tactics, moderately influential tactics, and low influential tactics and showed satisfactory reliability, a good model fit, and strong construct validity. Discussion: The findings provided good evidence of the Effectiveness Scale of Child Familial Influencing Behavior as a reliable tool with which to evaluate child familial influencing behaviors in a multigenerational context. Implications for further social work practice and research are discussed.