The invention is a mouse handled in hand, especially the mouse can be put both on a table surface and into a palm. The mouse comprises: at least one house; at least one switch button; a trackball, which is on a different surface of the house than a surface where the switch button is on; at least one brace apparatus, which supports the trackball when the mouse is placed at any angle; and at least one tracing trackball apparatus, which connects to the trackball to collect trackball rolling information. The tracing trackball apparatus comprises: at least two shading wheels, which have rims with gear shapes and two elongating arms against to the trackball; at least two reposition objects, which are behind elongating arms for elongating arms being tightly pushed onto trackball via elasticity; at least two photosensitive apparatuses, which are constructed by two sets of LEDs and light receivers, wherein between the LED and the light receiver is the shading wheel, therefore poking trackball to drive shading wheel, and simultaneously LED emits light to go through the gear shape of the rim of shading wheel for generating intermittent light signals; and at least one transform switch, which receives the intermittent light signals from photosensitive apparatuses, and when the mouse are on table upside down, both vertical and horizontal signals are just opposite, the transform switch is to alter signals.