A circuit design system 10 includes storage means 11 to store structure description information 11a of a reconfigurable circuit including an array of cells 1 including a plurality of switches 2, and application circuit netlist information 11b used to specify an application, circuit generation unit 12a to generate structure description information 11a based on the structure description information 11a and the application circuit netlist information 11b stored in the storage means 11, and circuit evaluation unit 12b to evaluate the structure description information 11a generated by the circuit generation unit 12a, wherein the circuit generation unit 12a generates the structure description information 11a by deleting at least one of the switches 2 from the structure description information 11a based on an evaluation result obtained by the circuit evaluation unit 12b.