It is intended to provide a sensor chip that enables detection of a deterioration state of a reagent applied on a reaction portion when measuring a concentration of a measurement object substance and a sensor system that enables a correct measurement by using the sensor chip for detecting the reagent deterioration state. A sensor chip including two substrates opposed to each other, a spacer layer sandwiched between the substrates, a multiple reaction portions provided in the spacer layer, and detection electrode units disposed on surfaces of the substrates facing to the spacer layer and exposed to the reaction portions, wherein an identical reagent A is applied on two or more of the reaction portions, and another reagent B that reacts with the reagent A is applied on at least one of the two reaction portions and a sensor system including the sensor chip and a measurement unit for comparing current values from the two or more reaction portions on which the identical reagent A is applied.