We study noncommutative geometry in the framework of the Batalin-Fradkin-Tyutin (BFT) scheme, which converts a second class constraint system into a first class one. In an open string, the theory of noncommutative geometry appears due to mixed boundary conditions having second class constraints, which arise in string theory with D-branes under a constant Neveu-Schwarz B field. The introduction of a new coordinate y on a D-brane through the BFT analysis allows us to obtain the commutative geometry with the help of the first class constraints, and the resulting action corresponding to the first class Hamiltonian in the BFT Hamiltonian formalism has a new local symmetry.