This study examines the selective migration process in China with a focus on age. The core argument is that China's internal migration overwhelmingly concentrates in young working-age adults, while their dependents, including children and the elderly, are often left behind in the origin villages. Moreover, when young working-age migrants become "old", they find it hard to stay in the destinations and have to return to the origins. In this way, "movement" or "migration" often does not lead to the expected end result of "settlement" in China. The great majority of migrant laborers are temporary as they cannot settle down, "burdenless" as they cannot bring dependents, and thus are more conveniently to be exploited. As such, the study interrogates the "low-cost" development model of China through the lens of age selectivity of migration, and contributes to the literature on China's economic development strategy, urban-rural dual system, and spatial politics of migration.