To provide a slippage detecting system capable of simultaneously detecting the slippage and a force and to provide a detecting system applicable to a care bed.

This slippage detecting system is provided with a detecting surface 9 mounted with an object 1 to be measured, a detecting means 2 detecting a force vector applied to the detecting surface 9 by the object 1 to be measured, a computing means 10 computing an XY force vector 13 and a gravity center displacement vector 14 based on the force vector detected by the detecting means 2 and its time changes, and a determining means 11, when the directions of the gravity center vector 14 and the XY force vector 13 are accorded within a predetermined range, determining the movement of the object 1 to be measured as the slippage.