Zhao Fei, minister of China's embassy in the UK, also attended the celebration and told attendees about the Chinese story at the heart of the pavilion.
"The story is known as Romeo and Juliet in the East," Zhao says.
This ending vividly portrays the pursuit of harmony and perfection by the Chinese people, he explains.
Henrietta Rous, one of the guests at the event, says she did not appreciate the significance of the pavilion and the story that inspired it before she attended.
"But now, having known the story, I've got quite involved and I'm very touched by the feeling that's gone into this pavilion," she says.
During the ceremony, Chinese opera singer Wang Beibei and two Italian musicians, Andrea Granitzio and Giovanni Pasini, performed an excerpt from an opera inspired by the story of the Butterfly Lovers.
Clare Matterson, director-general of the RHS, says the pavilion had become a much-loved landmark at Garden Wisley, and, as Chinese horticulture and design have had such an influence around the world, the RHS was delighted the pavilion had been restored.
"With all of my heart, it is a huge thank you to the China Chamber of Commerce in the UK and everybody here for the support in helping us to secure its future, the future of a beautiful celebration of Chinese culture and tradition in the very heart of our garden," she says.
Learning about the restoration of the pavilion, Liu, its designer, who was in Tianjin and could not attend the reopening, says: "I feel so proud that the Chinese pavilion still stands there, representing a mix of Chinese and British gardening culture.
"The lovely British summer will soon come, and butterflies will flutter in the garden again."