A hydrostatic transaxle, comprising: a transaxle casing (201,202,203,204); a pair of left and right axles disposed in the transaxle casing (201,202,203,204); a pair of hydraulic motors (M2,M3) for driving the respective axles, wherein the hydraulic motors (M2,M3) are disposed in the transaxle casing (201,202,203,204) so as to be fluidly connected to a common hydraulic pressure source in parallel to each other; a pair of left and right steerable drive wheels disposed on left and right outsides of the transaxle casing (201,202,203,204) so as to be drivingly connected to the respective axles; and a pair of left and right steerable casings operatively connected to a steering wheel, wherein the steerable casings are rotated according to operation of the steering wheel so as to steer the steerable drive wheels, characterized in that one of the hydraulic motors (M2,M3) is a fixed displacement hydraulic motor, and the other is a variable displacement hydraulic motor, wherein the hydrostatic transaxle comprises: a rod extended from one of the steerable casings; and a displacement control section (77,78,81) for controlling displacement of the variable displacement hydraulic motor, wherein the displacement control section (77,78,81) is connected to the rod so as to enable the change of displacement of variable displacement hydraulic motor according to change of steered angles of the steerable drive wheels. a transaxle casing (201,202,203,204); a pair of left and right axles disposed in the transaxle casing (201,202,203,204); a pair of hydraulic motors (M2,M3) for driving the respective axles, wherein the hydraulic motors (M2,M3) are disposed in the transaxle casing (201,202,203,204) so as to be fluidly connected to a common hydraulic pressure source in parallel to each other; a pair of left and right steerable drive wheels disposed on left and right outsides of the transaxle casing (201,202,203,204) so as to be drivingly connected to the respective axles; and a pair of left and right steerable casings operatively connected to a steering wheel, wherein the steerable casings are rotated according to operation of the steering wheel so as to steer the steerable drive wheels, characterized in that one of the hydraulic motors (M2,M3) is a fixed displacement hydraulic motor, and the other is a variable displacement hydraulic motor, wherein the hydrostatic transaxle comprises: a rod extended from one of the steerable casings; and a displacement control section (77,78,81) for controlling displacement of the variable displacement hydraulic motor, wherein the displacement control section (77,78,81) is connected to the rod so as to enable the change of displacement of variable displacement hydraulic motor according to change of steered angles of the steerable drive wheels. a rod extended from one of the steerable casings; and a displacement control section (77,78,81) for controlling displacement of the variable displacement hydraulic motor, wherein the displacement control section (77,78,81) is connected to the rod so as to enable the change of displacement of variable displacement hydraulic motor according to change of steered angles of the steerable drive wheels.