Formations of neuronal networks and body tissues are controlled by multi-cellular collective migration during embryonic development. Despite the fact that individually migratory cells show stochastic behaviors, the development is precisely regulated. Although such a property of single cell migration has been investigated, relationship between microscopic property of individual cell migration and macroscopic multi-cellular migration remains largely unknown. To explore this, we focused on migration of neural crest cells, during which cells collectively migrate accompanied with autonomous formation of stream. Computer simulations of our multi-cellular model suggested that the stochastic migration in the level of single cells works to efficiently achieve collective migration.