Abstract: A wind energy harvesting machine with three counter-rotating rotors in a duct is disclosed. The wind energy harvesting machine includes a tower, a duct, a counter-rotating generator with two rotary parts, and three groups of blades. The duct includes supporting static stators in front and rear and a static nose cone in the front. The counter-rotating generator has a main shaft and rotary interior and exterior parts to rotating in opposite directions. Three rotary blade groups including front and rear blade groups rotatable around the main shaft in the same direction, and a middle blade group rotatable in an opposite direction. The front and rear blade groups are displaceable axially along the main shaft and the middle blade group is fixed on the exterior part of the counter-rotating generator.