The present invention provides a washing machine and method of controlling a drying cycle thereof, by which a laundry can be evenly distributed within a drum (3) rotated at a second speed for a low-speed dewatering cycle during the drying cycle to further enhance a drying effect. Once the drying cycle is initiated, a blower fan (7) and heater (8) are driven to circulate hot air within the washing machine via tub (2) and circulation duct (6). And, the drum (3) is rotated by applying a first rotational speed for a normal drying cycle and a second rotational speed for a low-speed dewatering cycle with a prescribed duty ratio.