It had a maximum operating speed of 140 km/h (87 mph), but due to immature technologies, it never entered service.

The interest in EMUs arose again towards the end of the 1990s, with the catalyst being the 1999 World Horticultural Exposition, where it was realised that there was a need for short distance transport from Kunming to other nearby cities.

For this, Kunming bureau invested CN¥16,800,000 to construct an EMU,[2] signing a contract on 7 August 1998 with Changchun Railway Vehicles and Zhuzhou Institute.

[3] The KDZ1A was rolled out in March 1999, and sent to Beijing ring railway for tests, where it reached a maximum speed of 132 km/h (82 mph).

On 16 April 1999, days before the opening of the exposition, the KDZ1A participated in a ribbon cutting ceremony at Kunming station, and subsequently departed on service K439/440 from Kunming to Shiling,[4] and thus becoming the first commercially operated EMU in China, but was also the first streamlined EMU built.

[3] During the period of the Horticultural Exposition, there was a great demand for the service, and every trip ran at maximum occupancy.

The KDZ1A was put to use on the line from 1 June 2007, running between Kunming and Qujing on services T901/2 and T903/4, taking 106 minutes for the trip.

[6] However, due to limitations imposed by the neutral sections of the rail line, the KDZ1A was reduced to a four car formation with two motors and two trailers, lowering capacity to 372 people.

The motor car in the second traction unit carries the flat wave inductor and secondary inverters.