In 1998, Graham and his wife, Anthea, helped Briton Robert Glover establish the first China-UK joint venture charity, Care for Children, which has since placed 500,000 children in foster homes.

All these sincere gestures of friendship contributed to China's development and engagement with the outside world, across the fields of economics, finance, and people-to-people exchanges.

Statistics from the International Monetary Fund show China contributed 39 percent of global economic growth in 2016.

During the past 40 years, the country's GDP has grown by an average of about 9.5 percent a year, and more than 700 million Chinese people have been lifted out of poverty.

Graham sums up China's past 40 years as "priceless, so important to everybody, and it will determine the way in which China interacts with the world for generations".

"The most exciting thing of my lifetime is the way Deng Xiaoping really changed the whole direction China was traveling in," Graham said, adding that the sight of crowds of Chinese people all wearing Zhongshan suits will never be seen again, and that today's Western visitors will no longer feel different because of their attire.

China remains dedicated to the path of further reform and opening-up. At the opening ceremony of this year's Boao Forum for Asia, Xi pledged that China will take the initiative to expand imports and open China's domestic economy "wider and wider".

Graham stressed that he too believes it is imperative for China to continue its reforms. "As China becomes more self-confident, it will welcome more foreign businesses to have equal access in China, because it's the competition that drives up the quality," he said.