•A framework of constructive versus unconstructive involvement was identified.•Quality of mothers’ homework involvement varied with children’s homework behaviors.•Constructive involvement to child helplessness had academic and emotional benefits.•Unconstructive involvement to child helplessness had negative academic implications. Parents involve in children’s homework in qualitatively different ways. However, these qualitative aspects are usually understood in separate manners. This longitudinal study identified a unifying framework of constructive versus unconstructive involvement to grasp different qualitative aspects of parents’ homework involvement holistically. We also examined the implications of parents’ constructive versus unconstructive involvement for children’s academic and emotional functioning over time, with attention to parental involvement in two contrasting homework contexts where children showed helplessness or mastery. Chinese mothers (N = 370; Mage = 40.50 years, SD = 3.17) and their fourth graders (N = 370; 54.9 % girls; Mage = 9.90, SD = 0.33) participated in a two-wave longitudinal study spanning nine months. Confirmatory Factor Analyses identified a unifying framework of mothers’ constructive (featuring positive emotions, autonomy support, and mastery-oriented teaching) versus unconstructive involvement (featuring negative emotions, control, and performance-oriented teaching). Mothers involved more unconstructively and less constructively when children showed helplessness (vs. mastery). Mothers’ constructive involvement predicted children’s enhanced academic and emotional functioning over time, while mothers’ unconstructive involvement predicted children’s dampened academic functioning over time, with the associations mainly being significant in children’s helpless homework context. These findings highlight optimizing parents’ homework involvement quality, particularly when children face learning challenges.