An active structure of a semiconductor device. In one aspect, the active structure of the semiconductor device includes first to (n)th field regions, and first to (n+1)th active regions formed alternately with the first to (n)th field regions, wherein one or more of the first to (n+1)th active regions are connected at edge portions thereof to close one or more of the field regions. In another aspect, the active structure of the semiconductor device includes first to (n)th field regions, and first to (n+1)th active regions formed alternately with the first to (n)th field regions, wherein the first and (n+1)th active regions are connected to (n+2)th and (n+3)th active regions at edge portions thereof, closing the field regions.