The Y-12 started life as a development of the Harbin Y-11 airframe. The design featured numerous improvements including a redesigned wing with a new low drag section, a larger fuselage and bonded rather than riveted construction.
The first prototype, followed by about 30 production Y-12 (I) aircraft before a revised version was produced. This was designated the Y-12 (II), which featured more powerful engines and removal of leading edge slats, first flying on 16 August 1984 and receiving Chinese certification in December of the following year. The powerplants are two Pratt & Whitney Canada PT6A-27 turboprops with Hartzell propellers. The Y-12 has a maximum payload of 5,700 kg (12,600 lb) with seating for 17 passengers and two crew. The aircraft is operated as a light commuter and transport aircraft.
Y-12 (I) : Twin-engined STOL utility transport aircraft, powered by two 500-shp (373-kW) Pratt & Whitney Canada PT6A-11 turboprop engines. Prototype version.
Y-12 (II) : Fitted with more powerful PT6A-27 engines.
Y-12 (III) : Planned version to be fitted with WJ-9 turboprop. Evolved to Y-12C because of IV's success when WJ-9 development was completed.
Y-12 (IV) : Improved version. Revised wingtips (span increased to 19.2 m (63 ft)) and increased take off weight. 19 passenger seats. This version is the first aircraft ever certified by the FAA in 1995. 
Y-12C : Basically a (IV) version with WJ-9 turboprop, now used by PLAAF for aerial survey.
Y-12E : Variant with 18 passenger seats. PT6A-135A engines of equal horsepower but increased torque driving four-bladed propellers. This version was certified by the FAA in 2006.
Y-12F : Variant currently under development with wider fuselage, retractable landing gear and more powerful engines.
Turbo Panda : Export name for (II) version, marketed by England and Japanese companies. No real order due to airworthiness certification.
Twin Panda : Originally (II) version for export. Later a modified Y-12(IV) powered by two Pratt & Whitney Canada PT6A-34 turboprop engines and fitted with uprated undercarriage, upgraded avionics and interior. Thirty-five orders reportedly received by 2000 but production not proceeded with.
On 13 December 1993, a Lao Aviation Y-12-II, registration RDPL-34117, clipped trees in fog and crashed at Phonesavanh, Laos, killing all 18 on board.
On 4 April 1995, a TANS Y-12-II, registration 333/OB-1498, crashed shortly after takeoff from Iquitos Airport, Peru, killing all three on board.
On 21 June 1996, a China Flying Dragon Aviation Y-12-II, registration B-3822, crashed into a 100 m (330 ft) mountain near Changhai Airport after the crew began the final approach too early and deviated from the intended course, killing two of 12 on board.
On 20 January 1997, a Sri Lanka Air Force Y-12-II, CR851, crashed off Pataly Air Base while on a surveillance mission, killing all four on board.
On 10 June 1997, a MIAT Mongolian Airlines Y-12-II, registration JU-1020, crashed at Mandalgobi Airport due to windshear, killing seven of 12 on board.
On 26 May 1998, a MIAT Mongolian Airlines Y-12-II, registration JU-1017, crashed into a 6,500 ft (2,000 m) mountain near Erdenet, Mongolia en route to Mörön due to possible overloading, killing all 28 on board; this crash is the worst ever accident involving the Y-12.
On 19 October 2000, a Lao Aviation (now Lao Airlines) Y-12-II, registration RDPL-34130 and operating as Flight 703, crashed in a mountainous area in bad weather while on approach to Sam Neua, killing eight of 15 passengers; both pilots survived.
On 18 May 2005, a Zambia Air Force Y-12-II, AF-216, crashed shortly after takeoff from Mongu Airport, killing all 13 on board.
On 10 April 2006, a Kenya Air Force (KAF) Y-12-II, 132, struck the side of Mount Marsabit, killing 14 of 17 on board.
On 15 June 2008, a China Flying Dragon Aviation Y-12-II, registration B-3841, struck a small hill during a survey flight for a new aluminum mine, killing three of four on board.
On 12 July 2012, a Y-12 of the Mauritanian Air Force crashed while transporting gold, killing all 7 occupants.