Teheran Urban and Suburb Railway Corporation (hereinafter refers to as TUSK) ordered 217 Metro Vehicles manufactured by Changchun Car  Company  from  China  National  Technology Import-Export Corporation (hereinafter refers to as CNTIC)for Teheran Metro Line 1 and Line 2 on Mar.23,1995.
    Teheran Metro Line 1 (north-south) is served by 24 railway stations with a whole length of 28 km including 11.4 km under the ground, which has rare great gradients in the world including 50‰ gradient more that 6 km. Line 2 (east-west) is all under the ground and served by 19 railway stations with a whole length of 19.7 km, max. gradient of which is 35‰. The railway line and steel track comply with UIC standard and the track gauge is 1435mm. The nominal supply voltage is 750 VDC and adopts third-rail current collecting mode.
    Many great changes were made for the design of Teheran Metro Vehicles compared with that of previous vehicles to adapt the serious environment conditions and high-standard technical requirements as well as strictly limited manufacturing price of Teheran Metro, etc.
     Carbody steel structure is whole bearing thin-shelled cylindrical welding structure with its strength complying with some developed country's standard. High-grade paints are applied to its outside, Interior and exterior modelling are carefully designed by art-designer, with bright and beautiful color and tone. Wood structure is removed from the saloon interior decoration and equipment, all materials satisfy the nonflammable or non-combustive requirements, fireproof performance is increased. Latest technics or research achievements are applied to door, window, seat, wall plate, ceiling, floor, handrail, draftboard, illumination, ventilation system, heating system, public addre'ss system, etc. to make sue that the passengers have a safe and comfortable environment.
    The bogie is a new type of bolsterless bogie with the characteristics of light weight, simple structure, well performances and easy maintenance. The primary suspension is conic rubber with metal sandwich structure, secondary suspension is the bolsterless air spring with auxiliary rubber pile, with choke to produce damping effect. Pivot pin is adopted too make driving. Each bogie is fitted with four sets of block tread brake units including half of them with parking brake unit, and the motor bogie is also fitted with gear drving unit, current collector, anti-skid speed sensor, etc. The first bogie at head car is also fitted with rail guard, ATP signal sensor, tachometer motor, etc.
    Relatively cheap, well-performanced and practical chopping rheostatic control system is applied rather than the most advanced A.C. driving control system due to the price limit. Constant current starting is carried out by microprocessor-controlled thyristor regulating brake resistors smoothly when driving. There are one marshalling position and two running positions at driver's controller. When dynamic braking, dynamic brake force is obtained by microprocessor-controlled thyristor regulating brake resistors depending on the dynametic brake command. There are 15 brake grades for driver to select. The whole set of electric apparatus and equipment are the best and latest in the nation.
    The purpose of auxiliary power supply is to supply AC/DC power supply for vehicle systems or units of ventilation, illumination, control, charging, etc. Well-proven, durable and reliable motor-generator set is applied to supply three-phase A.C. power rather than the expensive static converter due to the price limit. Stable frequency and stable voltage unit is also fitted to make sure that stable frequency and stable voltage can be obtained at different loading and different line-voltage conditions. D.C. power supply is obtained by converting A.C. power with charging unit, for onboard D.C. supply and flotating charging of storage batteries. 
     Public address and safety alarm system is designed to central control, distrbuted amplification type and use IC card to memory stations information. The functions include: driver directly broadcasts to passengers, IC card announces stations, communicate between two driving cabs. There are still two alarm plates inside saloon which passengers can use (press the push-button on it )to alarm to driver at emergency circumstance, and can also communicate with driver.
    Air supply system includes electric piston type air-compressor, air dryer, etc. to make sure that the whole train has sufficient and clean compressed air.Advanced and safe analogue EP brake control system controled by micro-processor is adopted, which can be blended completely with the dynamic brake control system to make sure that the train obtain a stable comprehensive brake force. Considering that the dynamic brake has the failure possibility, to minimize the brake shoe wear at great gradient, this system can regulate dynamic brake force automatically to make sure that the dynamic brake force can be used to its maximum extent, i.e. carrying out international advanced seven-car cross-blending brake, and the system also has sensitive anti-skid unit and parking brake control unit etc.
    The ventilation system is of centralized type with four centrifugal motor fans fitted to each car ceiling and fresh air is transmitted to saloon through air ducts. Six cross-flow motor fans are fitted to increase the airflow speed of the saloon.Heaters which are fed with 750 VDC power are fitted under the seats.