The remarks on Wednesday were made in Mr Xi’s first public address since the US-China trade dispute escalated, with tariff hikes on both sides.
Mr Xi did not mention the US or the trade war directly, but focused on presenting China as an “open” country.
He said different civilisations were not destined to clash.
“Thinking that one’s own race and culture are superior, and insisting on transforming or even replacing other civilisations, is stupid in its understanding and disastrous in practice,” he told the Conference on Dialogue of Asian Civilisations in Beijing, which was organised the Chinese government.
“There is no clash between different civilisations, [we] just need to have the eye to appreciate the beauty in all civilisations,” he said.
Mr Xi added that China would only become more open to the world in the future.
“Today’s China is not only China’s China. It is Asia’s China and the world’s China. China in the future will take on an even more open stance to embrace the world,” he told the forum.
The conference on Wednesday, attended by the presidents of Greece, Sri Lanka and Singapore, was seen as being part of efforts by China to soften its image.
The communist country has faced criticism abroad for its tight cyber controls, the controversial Belt and Road infrastructure project that aims to expand global trade links, and its treatment of Muslims in the Xinjiang region, among other issues.
There have long been trade tensions between the world’s two largest economies, as both wrangle for global influence.
Since last year, they have placed billions of dollars worth of tariffs on each other’s goods.
But while optimism had grown recently over the prospect of a deal, tensions have again heightened in recent weeks.
Kiron Skinner, the director of policy planning at the US state department, last month described the US-China rivalry as “a fight with a really different civilisation and a different ideology”.
Mr Skinner said China was the US’s first “great power competitor that is not Caucasian”.
The US on Friday hiked tariffs on some $200bn (£155bn) worth of Chinese imports, as officials accused China of backtracking on its commitments.
China retaliated by saying it would introduce higher tariffs on $60bn worth of US goods from June.
Mr Xi is set to meet US President Donald Trump at the G20 gathering in Japan next month.
Mr Trump has said the US will make a deal with China “when the time is right”.