Three generations have documented the development of people-to-people ties between the two countries

After a summer rain shower, Qiu Xianglin takes his camera and walks along the Heilongjiang River, which serves as a boundary between China and Russia, hoping to capture a rainbow stretching over the river between Heilongjiang province's Heihe city and the Russian city of Blagoveshchensk.

"It is the most beautiful image I can capture," said 74-year-old Qiu, former chief photojournalist for Heihe Daily. For 40 years, he recorded the changes in Sino-Russian economic and trade cooperation, taking more than 100,000 photos.