Large-scale rural-urban migration over the past decades has led to the so-called “left-behind children” phenomenon in China. It is estimated that over 60 million children were left behind in villages after their parents migrated to cities for work. The LSCD survey seeks to explore how to measure the traits, skills, and preferences that determine important life outcomes for children, understand the development of the cognitive and non-cognitive skills of left-behind children, and examine the effects of early childhood interventions. Each year, the survey collects data from over 6,000 primary students in grades 4 to 6 (guardians and teachers included). So far, the SDC completed three waves in 2017, 2018, and 2019. Professor James J. Heckman acts as an advisor to this survey and helps to develop its research design.