The 1st and 2nd generation Class 351000 trains used an ivory-colored interior with a long sheet prior to their overhauls.

Trains 351-19~351-22 were manufactured in 1999 by Hanjin Heavy Industries to expand the rolling stock on Bundang Line.

[citation needed] The second generation of Class 351000 trains were built in 2003 by ROTEM (Railroading Technology System) to address the extension of the Suin-Bundang Line from Suseo station to Seolleung station.

The car body as a whole was redesigned; the cab ends of the driving cars were changed completely, and the side windows are now coated and in a single piece (as opposed to the two-window setup between doors).

Because of the circular front view, the trains are nicknamed "round face" (동글이).

The third generation Class 351000 trains were built from 2011 to 2017 by Hyundai Rotem to address numerous extensions of the Suin-Bundang Line.

The interior was also updated, and the door motors are now electric-powered as opposed to air-powered.

These sets serve as replacements for aging first generation Class 351000 trains.

[citation needed] The first and second generation Class 351000 trains were overhauled from 2003 to 2005 (though minor refurbishments were started in 2002).

The Daegu subway fire compelled Korail to introduce flame-resistant interiors for passenger safety.

All first and second generation trains featured a livery consisting of red and orange stripes.

In 2011, the 1st and 2nd generation Class 351000 trains were renumbered from the 2030-series to the 351000-series as a part of a new numbering scheme by Korail (the leading "3" indicating a metro car).