A drawing of Queen Elizabeth receiving Chung Attai in 1851.

"I didn't know that China had attended World Expo every time and a Shanghai businessman named Chung Attai was honored by Queen Elizabeth in 1851 until I saw your collection," commented exhibition-goer Lin Qi, on Tong's website.

"At the exhibition, a lot of people, including some professional collectors, came to me showing their astonishment at the unknown history and respect for my seeming-ly-impossible project," Tong said excitedly.

"Aside from the joy of uncovering hidden history, letting more and more people know about history through my collection also gives me great joy," he added.

The process of collecting, however, is time-consuming work. Always engrossed in extensive research, Tong normally spends hours online every day looking for new pieces and at old collections.

He attributes much of his success to the convenience of the Internet.

"Because most of the collections of World Expo pieces are abroad, with the help of the Internet, I have bought a large number of my collection online from ebay and some personal galleries," Tong explained.

In the space of seven years, Tong has collected some 300 medals and old pictures of World Expos and has gained much more than an impressive set of paraphernalia.

"It helps me maintain a simple attitude amid the ups and downs in my life," Tong said.

Expos are just a part of Tong's collection. He added that he may soon exhibit his interesting series of 62 photographs depicting the life of Chinese