The Dong-Feng 21 (DF-21; NATO reporting name CSS-5 - Dong-Feng (Chinese: 东风; literally: "East Wind")) is a two-stage, solid-fuel rocket, single-warhead medium-range ballistic missile (MRBM) in the Dong Feng series developed by China Changfeng Mechanics and Electronics Technology Academy. Development started in the late 1960s and was completed around 1985-86, but it was not deployed until 1991. It was developed from the submarine-launched JL-1 missile, and is China's first solid-fuel land-based missile. The U.S. Department of Defense in 2008 estimated that China had 60-80 missiles and 60 launchers;approximately 10-11 missiles can be built annually.
Dong-Feng 21型（DF-21；北约代号CSS-5 -东风（中文：东风；字面上的意思：“东风”））是由中国Changfeng力学和电子技术学院发展的东风系列中一种二级、固体燃料火箭发动机，单弹头中程弹道导弹（MRBM）。发展始于20世纪60年代末和在1985-86年完成，但在1991年之前没有部署。它是基于潜艇发射的JL-1导弹发展，是中国第一种固体燃料陆基导弹。美国国防部在2008年估计中国有60-80枚导弹和60套发射装置；每年大概能制造约10-11枚导弹。
Originally developed as a strategic weapon, the DF-21's later variants were designed for both nuclear and conventional missions. As well as a nuclear warhead of around 300 kt, it is thought that high explosive and submunition warheads are available. The latest DF-21D was said to be the world's first anti-ship ballistic missile (ASBM). The DF-21 has also been developed into a space-capable anti-satellite weapon/anti-missile weapon carrier.
Though the launcher itself is mobile to reduce vulnerability, an actual launch unit requires support vehicles that can cover a 300×300-meter area, making it hard to move quickly and easier to detect. Also, the launcher is not made to travel off-road and requires solid ground when firing to prevent backblast and debris damage due to the hard launch, restricting its firing locations to roads and pre-made launch pads.
DF-21/A/C (CSS-5 Mod-1/2/3)
The basic variant DF-21 had a range of 1,770+ km,and a payload of 600 kg (1,300 lb) consisting of a single 500 kt nuclear warhead, with an estimated circular error probable (CEP) of 300~400 m; this version did not enter operational service.The DF-21A was operational by 1996 and has improved accuracy with an estimated CEP of 100~300 m.This version is reported to have a similar 1,770+ km range,with a potential extended range of 2,150 km (1,340 mi).
基本型导弹射程1770多公里，有效载荷600公斤（1300磅）包括一枚500千吨当量的核弹头，估计圆概率误差（CEP）300 ~ 400米；这个型号没有进入操作服役。DF-21A操作时间在1996年并提高了精度圆概率误差（CEP）估计有100 ~ 300米。这个型号据报道大约射程1770公里，潜在射程到2150公里（1340英里）。
Revealed in 2006, the DF-21C is a terminally guided version that has a maximum range believed to be about 1,700 km (1,100 mi) and accuracy estimated to be 50~10 m.The missile was the first dual-capable version, able to be armed with either a nuclear or conventional warhead. In 2010, the DF-21C was being deployed in central Western China.
在2006年披露，DF-21C是一种末制导型号，最大射程被认为约1700公里（1100英里）和精度估计为50 ~ 10米。导弹是第一种两用型，可携带核或常规弹头。2010年，DF-21C被部署在中国西部中心。