In the late 1960s, the Chinese Army (PLA) introduced a new, indigenous tracked vehicle for the Armored Personnel Carrier (APC) role as the "Type 63" (also "YW531"). About 8,000 of these were eventually produced under the NORINCO brand label and many went on to see combat action (in foreign hands) in later wars such as Vietnam, Iran-Iraq, and the 2003 U.S.-led invasion of Iraq. From this base design came about many other forms using the same underlying mechanical works and among these developments was the "Type 70" MRL ("Multiple Rocket Launch") rocket artillery vehicle also known under the designation of "Type WZ303". A Self-Propelled Artillery (SPA) also existed as the Type 70 SPH / WZ302.
The Type 70 MRL retained the original vehicle's drive system - four road wheels to a hull side with the drive sprocket at front, the engine front-right, and the track idler at rear. The driver sat front-left with the rear section of the hull reserved for a turreted rocket-launching system. The launch unit was made up of nineteen 130mm tubes and offered inherent traverse and elevation controls allowing the vehicle to face any direction and still remain capable of engaging enemy positions. Each one-meter-long, 72 lb rocket held a 32.5 lb High-Explosive, FRAGmentation (HE-FRAG) warhead with a range out to 11,060 yards.
Beyond the addition of the launcher, the YW531 APC hull remained largely the same. Drive power was through a KHD BF8L 413F series 8-cylinder, air-cooled, turbocharged, diesel-fueled engine of 320 horsepower. This provided the vehicle with a maximum road speed of 65 kmh and an operational range out to 500 kilometers. The hull was suspended atop a torsion bar arrangement allowing for some cross-country mobility.
With the modifications in place, the Type 70 MRL vehicle provided the Chinese Army with a capable and relatively inexpensive fire support system firing large salvos of rockets against enemy positions at range. Such firepower covered an extensive area and served double-duty as a psychological tool against enemy infantry as much as a battlefield-impact weapon. It is understood that the Type 70 MRL was succeeded by the Type 89 series sometime in the early 1990s - though it is entirely possible that many Type 70 MRL vehicles still remain available to the PLA through storage or held in reserve.