DES-28~DES-31 metro cars were built for Fu-Ba Line of Beijing Subway before 2001. The train-set adopt VVVF inverter, contract-free main circuit, AC motor without commentator and brush-gear, which can make full use of adhesion, longer lifetime and less maintenance.

The car features Cor-Ten steel thin tube bearing broad-body and non-bolster bogie, micro-computer controlled analogue E-P brake system, static inverter auxiliary power supply, train-set monitoring system, air conditioning unit, automatic public address, coach emergency alarming device, automatic train operation system and radio communication equipment.