A planetary gear train of an automatic transmission may include an input shaft; an output shaft; first to fourth planetary gear sets and six control elements disposed at a portion selectively connecting the rotation elements and the rotation elements or a portion selectively connecting the rotation elements and the transmission housing, wherein the input shaft is continuously connected to the third rotation element, the output shaft is continuously connected to the twelfth rotation element, the first rotation element is continuously connected to the transmission housing, the fourth rotation element is continuously connected to the seventh rotation element, the fourth rotation element is continuously connected to the tenth rotation element, the eighth rotation element is continuously connected to the twelfth rotation element, the fifth rotation element is selectively connected to the transmission housing.