"They call me the Olympic stamp guy and now many of them will save the good stuff for me," he said.
One of his most memorable experiences relates to Chinese sprinter Liu Changchun (1909 - 83), the first Chinese Olympian and a pioneer of China's sports who took part in the 1932 and 1936 Olympic Games.
What Tu was looking for was Liu's stamp with a postmark of the opening day of the 1932 Los Angeles Games. He bought several stamps through friends in the United States but none of the postmarks had the right date.
"I had already spent over 1,000 yuan on this collection and I was getting a bit frustrated. But fortunately I happened to get it from a local stamp trader and it only cost me 100 yuan," he said.
"What I want now is the signature of Liu Changchun."
It is very difficult to get Liu's signature because the Olympian had tried to keep a low profile, he said. He died in 1983.
Olympic wishes
Tu has two Olympic wishes: to become a torchbearer and to hold exhibitions overseas.
As the only representative for the millions of Chinese stamp collectors, Tu took part in the 2008 Olympic torchbearer selection. His passion for the Olympic movement and the large collection won over 80,000 votes in the competition. Now he has been shortlisted in the final round.
He said the relationship between stamp collectors and the Olympic Games dates back to 1896 when the first Olympic Games was held in Athens. Two Greek stamp collectors suggested the local government launch a set of Olympic stamps to raise money for the venue construction. The government officials took heed and half of the revenue was poured into the venues.
"There was no one representing Chinese stamp collectors during the 2004 Athens Olympic torch relay in Beijing, so this time I want to become the first one from our group," Tu said.
He also wants to pass his Olympic passion on to people outside China.
"I want to display my collections in Athens and Los Angeles," he said.
"Athens is the home of the Olympic Games and Los Angeles is the place where the first Chinese Olympian competed, and where Xu Haifeng took China's first Olympic gold."