The line between Nagata Station and Ikoma Station was constructed as the Higashi-Osaka Line for the purpose of bypassing the Kintetsu Nara Line, whose cars had become seriously congested due to the development of land for housing along the line.
長田～生駒間は東大阪線として、沿線の宅地開発が進み混雑が激しくなった近鉄奈良線のバイパスとして建設された。