A sensorless three-phased brushless direct current (BLDC) motor comprises a stator, a rotor and a driving unit. The stator has a first-phased coil, a second-phased coil and a third-phased coil. Each of the first-phased, second-phased and third-phased coils has a varying inductance value. The varying inductance value has an inductance changing rate greater than 15%. The rotor has a plurality of magnetic poles, each having a magnetic pole face facing the stator. The driving unit has a power input end and a signal input/output end. The signal input/output end is coupled to the first-phased, second-phased and third-phased coils, and the power input end is used to receive power for maintaining operation of the driving unit.