A method of signal processing for a sensitive signal generated from a pointing device, which comprises the steps of acquiring an accelerating signal; forming a filtering signal by a first filtering process to filter the accelerating signal; and processing a second filtering process to form a processed signal. By means of the aforesaid method, an inertia pointing device is disclosed in the present invention, which is capable of processing an accelerating signal generated from the movement of the pointing device operated by the user, and transmitting the processed signal to an electrical device. The electrical device is capable of generating a corresponding displacement for moving a cursor on the display or action for controlling an object according to the processed signal.