Homework is not only an extensively-applied instructional instrument but also the most important learning activity for students after class. Despite the long history of homework research, the role that homework plays in enhancing student achievement is not thoroughly understood. The purpose is to explore the relationship between homework and academic achievement through reviewing the homework research. The conclusions can help teachers to assign homework and help students to study more effectively. From the characteristics of homework, the process of homework completion, parental involvement in homework and the mechanism underlying the effects of homework on study, the article explored the relationship between homework and academic achievement. Finally, the author pointed out the practical values and the further directions of research in this field. Most studies supported the conclusion that homework can improve academic achievement. Firstly, the characteristics of homework can affect students’ achievement. Researchers found positive association between homework time and achievement. Meanwhile, the relationship can be moderated by the age or grade of students. The appropriate amount of homework is conducive to high achievement. The proper strategies teachers adopt during homework assignment can enhance academic achievement. The recent studies obtained some new results. The strength and direction of the homework-achievement association depend on the homework indicator chosen and differ to some degree across analytical levels. Secondly, the process of students’ homework completion relates to their academic achievement. Some results showed that there were different patterns of preferred homework styles between high- and low-achieving groups. High achievers value their homework more, put forth more effort and are more persistent, as compared to low achievers. After then, the relationship between parental involvement in homework and academic achievement were discussed. If the parents are tought to improve the students’ completion of homework and help students to manage their homework behavior, the students’ achievement can be enhanced. Finally, the mechanism underlying the effects of homework on study were summarized.There are several suggestions for teachers and parents. The teacher should pay attention to the individual differences among students when they are assigning homework. They should select the most proper mode and homework materials to increase students’ interest and homework completion. Parents and teachers should cultivate children’s self-regulatory capability and good homework styles. All of these are helpful to enhance students’ achievement. At last, the author pointed out the further directions of research in this field. Homework is the most complicated learning activity. Many variables have effects on the relationship between homework and achievement. So the future research should discuss their relationship more detailedly from various angles. According to the systemic model of homework, learning environment, teacher, student characteristics and role of parents influence homework behavior jointly. How do these factors determine the effect of homework? Researchers should expand the research in the future. Because of nested data in homework research, the researchers should pay more attention to multilevel model to explore the relationship between homework and academic achievement. The author argued that homework research should be more closely associated with well-founded psychological theories of learning and instruction.