An object determining system, comprising: an optical sensor, comprising a kind determining region and an element analyzing region, wherein the optical sensor acquires first optical data via the kind determining region, and acquires second optical data via the element analyzing region, wherein the kind determining region and the element analyzing region are different regions of the optical sensor; a kind determining circuit, configured to determine an object kind of the object according to the first optical data; and an element analyzing circuit, configured to analyze element of the object according to the second optical data.