Riding a wooden horse, a toddler is smiling in a black-and-white photo that is being exhibited at an old photograph fair in north China at the Pingyao Photography Festival (PIP).
Liu Yaping collected the photograph from a waste picker in Shanghai. "The old photograph records the childhood of the kid and also the history of our own," Liu said.
Liu owns more than 3,000 pictures of children from 1895 to the modern day. "I am considering building up a database," he said.
Collectors from home and abroad are attending the old photograph fair, bringing thousands of pictures for display.
The earliest one dates back to 1859, reflecting China's folk custom photographed by an American surnamed Underwood.
"Old photographs provide backgrounds for us to understand history," said Gerald Pryor, an associate professor of art and science with New York University.
For him, collecting old photographs is a preservation of memory and a good way of knowing China.
"Each old photo bears a story and countless stories can be told from them," said Zhu Yixiang, vice president of a Shanghai-based old photo collection saloon, the first of its kind in China that was established in 2010.
With more than 40 registered professional collectors, the saloon has conducted a joint exhibition of old photographs, ranging from the country's first tramcar to those taken during the Cultural Revolution in the 1960s and 1970s.
A zeitgeist of nostalgia has emerged among people, Zhu said, adding that more and more people are keen on collecting old photographs.
"Photography was not introduced in China until 1867 and then it was only a privilege of the rich," Zhu said.
In Beijing Huachen auction house, a 180-piece-series of Zhou Xuan, a female singer from Shanghai during the early decades of the 20th century, was sold for about 2 million yuan ($ 317,460), according to Zhu.
A man surnamed He in his 50s, has a series of Mao's photographs published by Xinhua News Agency in 1971 in celebration of the 50th anniversary of the founding of the Communist Party of China. Some photos are rarely seen today.
"I don't want to sell the old photos of Chairman Mao. I just came to show them to the public and express our gratitude to him," He said.