Abstract: In 2009, China for the first time surpassed the U.S. with an advantage of three million cars as the world’s automobile production and sales superpower, five to six years earlier than expected. China’s automobile market’s outstanding performance, not only effectively stimulates China’s domestic automobile industry chain development, but also has made tremendous contributions to worldwide automotive industry during global economic crisis. However, the “first” bring not only joy, also more pressure to China. Compared with the world automotive powers, China’s auto industry is still weak in technical level, R&D innovation, brand influence and international competitiveness. At the same time, automotive industry has posed great pressure on China’s energy security, low carbon economy and a huge burden on the urban environment, which is restricting automotive industry’s development in turn. The transition is extremely urgent. As an important means to reduce oil consumption and exhaust emissions, automotive lightweighting has been attached great importance, and has become the important means for the world automobile power to improve their brand competitiveness. The means and trends of worldwide car body lightweighting are reviewed, the challenges of lightweight body to joining technologies are analyzed, and newest technologies proposed to meet the challenges are also reviewed. Hopefully this study will provide a useful reference to lightweight car body’s design and manufacturing in China.

Key words: Car body, Lightweight, Multi-material mix, Welding and joining