A pointing device (100, 100'), used with a computer device and capable of being operated in either an mouse-operating mode or an holding-a-pen-operating (HAPO) mode, the pointing device (100, 100') comprising: a base comprising: a first hinge portion located on one end of the base; and a main body comprising a second hinge portion and a processing unit, the second hinge portion located on one end of the main body and pivoted on the first hinge portion, and the processing unit located in the main body; wherein the pointing device (100, 100') is characterized by: the base further comprising a displacement sensing module located at a bottom surface of the base to detect displacement of the base and generate a displacement signal; wherein the processing unit is electrically connected to the displacement sensing module for receiving the displacement signal and transmitting the displacement signal to the computer device; wherein the main body and the base are selectively rotated to have either a first angle or a second angle therebetween, and the displacement sensing module is configured to detect displacement and generate a displacement signal if the main body and the base have the first angle therebetween, as well as have the second angle therebetween; wherein if the main body and the base have the first angle therebetween, the pointing device (100, 100') is operated in the mouse-operating mode; otherwise, the pointing device (100, 100') is operated in the HAPO mode. a base comprising: a first hinge portion located on one end of the base; and a main body comprising a second hinge portion and a processing unit, the second hinge portion located on one end of the main body and pivoted on the first hinge portion, and the processing unit located in the main body; a first hinge portion located on one end of the base; and a main body comprising a second hinge portion and a processing unit, the second hinge portion located on one end of the main body and pivoted on the first hinge portion, and the processing unit located in the main body; wherein the pointing device (100, 100') is characterized by: the base further comprising a displacement sensing module located at a bottom surface of the base to detect displacement of the base and generate a displacement signal; wherein the processing unit is electrically connected to the displacement sensing module for receiving the displacement signal and transmitting the displacement signal to the computer device; wherein the main body and the base are selectively rotated to have either a first angle or a second angle therebetween, and the displacement sensing module is configured to detect displacement and generate a displacement signal if the main body and the base have the first angle therebetween, as well as have the second angle therebetween; wherein if the main body and the base have the first angle therebetween, the pointing device (100, 100') is operated in the mouse-operating mode; otherwise, the pointing device (100, 100') is operated in the HAPO mode. the base further comprising a displacement sensing module located at a bottom surface of the base to detect displacement of the base and generate a displacement signal; wherein the processing unit is electrically connected to the displacement sensing module for receiving the displacement signal and transmitting the displacement signal to the computer device; wherein the main body and the base are selectively rotated to have either a first angle or a second angle therebetween, and the displacement sensing module is configured to detect displacement and generate a displacement signal if the main body and the base have the first angle therebetween, as well as have the second angle therebetween; wherein if the main body and the base have the first angle therebetween, the pointing device (100, 100') is operated in the mouse-operating mode; otherwise, the pointing device (100, 100') is operated in the HAPO mode.