According to the existing national codes Code for Design of High Speed Railway, Code for Design of Railway Station and Terminal and Code for Design of Metro, this paper analyzed the influencing factors for the distance between turnout and horizontal curve of rail transit in city region. The calculation methods and results of distance between turnout and horizontal curves of rail transit in city region were calculated by considering railway vehicle parameters of Wenzhou, target speed of the railway line, extra height and width of turnout con- nected with curves, turnout size and the structure of frog, line property of turnout laying, and the impacts of rail structure on distance between main line portion of turnout, auxiliary line turnout, yard track turnout and horizon- tal curves.