A controlled rolling method of a seamless steel tube excellent in strength and low-temperature toughness to be applied to a process of making a seamless steel tube in which using a round steel bar (billet) heated at a predetermined temperature in a heating furnace, a piercing-rolling step, an elongation rolling step, and a reducing rolling step are carried out, the reducing rolling step being performed, if needed, after reheating treatment, characterized in that the controlled rolling method comprises: in the piercing-rolling step, performing piercing-rolling in a recrystallization region of a γ phase, the recrystallization region of the γ phase being characterized by a temperature of 950°C or more, wherein an inclined cross piercing mill having cone-type main rolls is employed, and diameter-expansion piercing at an expansion ratio of 1.05 to 2.50 is applied by setting a cross angle of 3° to 30° and a feed angle of 5° to 18°; at least in the elongation rolling step, performing elongation rolling within the non-recrystallization region of the γ phase, the non-recrystallization region of the γ phase being characterized by a temperature of the Ar3 transformation point to 950 °C; then, in the reducing rolling step, performing the following (a) or (b); and performing controlled cooling or quenching immediately after the reducing rolling: (a) performing reducing rolling within the non-recrystallization region of the γ phase; or (b) performing reducing rolling in a (α + γ) dual phase temperature region, the (α + γ) dual phase temperature region being characterized by a temperature of the Ar1 transformation point to the Ar3 transformation point, using a sizer as a reducing rolling mill. in the piercing-rolling step, performing piercing-rolling in a recrystallization region of a γ phase, the recrystallization region of the γ phase being characterized by a temperature of 950°C or more, wherein an inclined cross piercing mill having cone-type main rolls is employed, and diameter-expansion piercing at an expansion ratio of 1.05 to 2.50 is applied by setting a cross angle of 3° to 30° and a feed angle of 5° to 18°; at least in the elongation rolling step, performing elongation rolling within the non-recrystallization region of the γ phase, the non-recrystallization region of the γ phase being characterized by a temperature of the Ar3 transformation point to 950 °C; then, in the reducing rolling step, performing the following (a) or (b); and performing controlled cooling or quenching immediately after the reducing rolling: (a) performing reducing rolling within the non-recrystallization region of the γ phase; or (b) performing reducing rolling in a (α + γ) dual phase temperature region, the (α + γ) dual phase temperature region being characterized by a temperature of the Ar1 transformation point to the Ar3 transformation point, using a sizer as a reducing rolling mill. (a) performing reducing rolling within the non-recrystallization region of the γ phase; or (b) performing reducing rolling in a (α + γ) dual phase temperature region, the (α + γ) dual phase temperature region being characterized by a temperature of the Ar1 transformation point to the Ar3 transformation point, using a sizer as a reducing rolling mill.