Abstract: Disclosed is an apparatus and a method for controlling a rotation speed of a motor. The apparatus includes a detector electrically connected to said motor for generating a first detection signal corresponding to a feedback signal output from said motor; and a controller electrically connected to said motor and said detector for receiving said first detection signal. When said motor rotates at a relatively low rotation speed, said controller generates a first control signal with a first frequency to be output to said motor corresponding to said first detection signal; when said motor rotates at a relatively high rotation speed, said controller generates a second control signal with a second frequency to be output to said motor; wherein said first frequency of said first control signal is greater than said second frequency of said second control signal.