During what was dubbed as a "super state visit" to Britain, President Xi Jinping witnessed the signing of deals worth 40 billion pounds (61.5 billion U.S. dollars).
The most talked-about project will see China holding a one-third stake in Britain's first new nuclear plant in a generation.
Observers are praising the China-Britain partnership as exemplary in China-Europe cooperation and beyond.
CHINA, BRITAIN'S BIG POWER DIPLOMACY
China's approach to dealing with major powers was clarified by Xi during his visit to the headquarters of the United Nations; a relationship featuring non-conflict, non-confrontation, mutual respect and win-win cooperation.
His state visit to Britain was regarded as many as a test for China's diplomacy with big powers, and it has proven to be fruitful.
Britain rolled out the red carpet for Xi, the first Chinese head of state to visit the country in a decade. Queen Elizabeth II hosted an informal lunch and formal banquet. While Prime Minister David Cameron took Xi to see that age-old British institution -- the pub.
"The Financial Times" said Xi's visit was the "most important diplomatic visit to Britain in several years," and would recalibrate the UK's great-power relations."
During the visit, China and Britain issued a joint declaration on their "global comprehensive strategic partnership for the 21st century," which will usher in a lasting, open, win-win "golden era."
"The new definition of bilateral ties reflects both countries expect to achieve win-win cooperation with each other, but not only at the bilateral level," said Feng Zhongping, vice president of China Institutes of Contemporary International Relations.
As globally-influential countries, the China-Britain partnership can set an example for China-Europe cooperation and at the global level, Chen Xin with the Chinese Academy of Social Sciences said.
"Though there are disagreements between China and Britain, both countries can learn to manage them. As long as Britain adheres to the consensus reached with China, the differences won't affect bilateral cooperation," said Cui Hongjian, a researcher at the China Institute of International Studies.
NUCLEAR DEAL, ECONOMIC TIES
Chinese and French companies signed an agreement to build an 18 billion pound nuclear power plant at Hinkley Point C, with the CGN-led Chinese consortium holding a one-third stake.
Cameron described the Hinkley Point C project as "historic" as it would provide clean electricity to nearly 6 million homes and create over 25,000 jobs.
