The demand response system comprises an automatic meter reading (AMR) unit to generate metering information. The demand response system comprises a multiple utility complex unit (MUC) which provides DR information based on the metering information and manages utility supply schedule in combination. The demand response system comprises an eco index (EI) calculation unit which calculates an eco index based on the metering information. The demand response system comprises a demand response (DR) unit which obtains the CBL information based on the metering information and computes a the DR bill by using the CBL data, the DR information and EI obtained, and outputs the DR bill. The demand response system comprises a smart portal (SP) unit which provides users with the calculated DR bill. According to the disclosure, the demand response system can provide environmental and social information, in addition to economic information.