The tour guide believes it is his responsibility to pass it down and let more people know about it

Every day, He Runyuan explains what happiness is to hundreds of tourists.

"Dongba symbols are used by China's Naxi ethnic group and are some of the world's only remaining pictographs. For them, happiness is a steaming hot pot of food," He said. "As it was in the past, having a hot meal means everything."

Dressed in traditional Naxi costume of a goatskin vest and a white robe, He guides tourists to learn Naxi scripts, history, culture and tradition at his center of Naxi Dongba pictographs and paintings in the Old Town of Lijiang, Southwest China's Yunnan province.

"Peak seasons such as national holidays, summer and winter vacations see around 5,000 visitors a day," the 42-year-old said.

"After explaining the symbols, I will ask tourists to pick one they like and try to write it."

As a Naxi person, He grew up in the Old Town, a UNESCO World Heritage Site with an 800-year history. The town attracted more than 14 million tourists last year.

For about 30 years, He has been learning Naxi painting and pictographs. "With a population of more than 300,000, less than 700 Naxi people understand Dongba pictographs, and only a few can do traditional Naxi paintings," he said.