[Photo by Jiang Dong/China Daily]

He estimates that about one-third of the ancient books being cataloged in the national list are damaged. But he says it doesn't mean that they all need being repaired right away.

Li Jining, a researcher with the national library, says the main principle is "to save life in the first place"－as little restoration as possible unless an ancient book is in a very poor condition.

"For example, the original paper also carries a lot of important information and should be kept as it is if it is not badly torn."

He says the materials used for mending should in the future be able to be replaced by better ones, and the repairs need to be recorded for reference by researchers later.The market price of rare ancient books has risen in recent two years. A copy of Mile Shangsheng Jing printed during the Five Dynasties period was sold for 5 million yuan ($750,000) at a Beijing auction on June 5.

Zhang says the exhibition should encourage private collectors to make donations or conduct transactions on lower prices so that more people benefit. He declines to reveal how much the three Buddhist texts on show cost the national library.

Contact the writer at linqi@chinadaily.com.cn

If you go

9 am-5 pm, Tuesdays to Sundays, through July 21. National Library of China, 33 Zhongguancun South Street, Haidian district, Beijing. 010-8854-4747.