During his 15-day trip to Kathmandu, Yu took pictures of 96 children and 76 families at the Chuchepati relocation camp. [Photo provided to China Daily]

"We must gather all the members of each family together, otherwise they are not true family photos," he told the volunteers.

An old Nepalese man made the biggest impression on Yu. The man followed him every evening while he was shooting the family photos. Yu later learned that the old man had lost all his family members during the earthquake and now lived by himself, so Yu took a photo of the man and gave it to him.

As a reward for his volunteers, Yu gave three photography classes at the camp. He taught them how to use a camera, taking pictures of a dog and each other. Their last assignment was to take a photo of an important person in their life and write something about that person on the back of the photo.

"I wanted to teach them how to express love and appreciation as well as the purpose of photography," Yu said. One boy took a picture of Yu and wrote, "I wish you could stay."

Eventually, Yu ran out of photo paper and had to conclude his trip.

"It was a pity. I wish I could have taken more," he said.

Motivated by his experience, Yu plans to continue his family photo project at home and abroad.

"I want to gather more photographers and take pictures of Chinese migrant workers during Spring Festival," he said. "Also, I will probably go back to Nepal."