XINING, Jan. 9 (Xinhua) -- A 1,260-meter thangka, a traditional Tibetan Buddhist scroll painting, is expected to be completed in spring in northwest China's Qinghai Province, becoming world's longest thangka.

Previously, a 618-meter thangka was considered the world's longest.

The painting is 2 meters high and depicts the whole life of Tsongkhapa, founder of the Yellow Hat Sect of Tibetan Buddhism.

Since 2010, more than 380 painters have participated in the project, completing about 1,100 meters so far.

Thangka is a form of silk painting that dates back to the Tibetan Tubo Kingdom 1,200 years ago. It was listed as UNESCO Intangible Cultural Heritage in 2009.