Internal migration in China went through three main phases: phase 1 saw the implementation of the Hukou system in 1958 to strictly control rural-urban migration; phase 2 from 1980 encouraged short-distance migration for small businesses but long-distance migration still occurred, creating a "floating population" of 100 million by 1990; and phase 3 introduced temporary residence permits in the late 1980s to fuel industrialization and allow massive migration surges to major eastern cities while still withholding full Hukou rights.