The notion that “space is persistent” has been widely accepted without explanation and incorporated into the interpretation of Kantian philosophy. But within the framework of Kantian philosophy， the use of “persistence” to describe “space” is problematic， nor is it sustainable to treat the space as the basis of possibility for all persistence. Nevertheless， the formation of the notion that “space is persistent” as an everyday belief can well be traced. The conceptual-genealogical approach reveals that the inner logical clue of the formation of this notion consists in the implicit relationship and conversion between the concepts “simultaneity”， “persistence” and “spatiality” in Kant’s transcendental philosophy.