This paper utilizes data from the China Education Panel Survey 2013-2015 to examine the effects of family time and money inputs in education on adolescent academic performance from the perspectives of home social capital, cultural capital, and shadow education. Home time input in education is more vital to teenager academic progress than money input. Domestic social capital and cultural capital as well as weekend shadow education positively impact child academic results. Home-based parental participation as a key component of domestic social capital has the most significant influence on teenager academic improvement, while weekend supplementary tutoring generates the weakest effect; workday extracurricular tutoring even negatively affects student academic achievement. School-based parental involvement differs among families of different classes, with a significant negative effect on academic results of teenagers from disadvantaged backgrounds. Due to the absence of heterogeneity effects of home time input in education on academic progress of students from various social backgrounds, parental time investment should be taken as the most effective means to improve academic performance of adolescents from underprivileged classes.