XINING, June 20 (Xinhua) -- A fair on green development opened Thursday in northwest China's Qinghai Province.

The 20th Qinghai China Investment and Trade Fair for Green Development opened in the provincial capital Xining, with about 13,000 business delegates from home and abroad in attendance.

The fair has an exhibition area of 61,500 square meters, the biggest since the first fair opened in 2000. The main venue is in Xining, with 10 exhibition areas. A sub-venue is set up in the city of Delingha, which hosts more than 50 activities ranging from forums to investment promotions.

A total of 249 projects worth about 140 billion yuan (20 billion U.S. dollars) are expected to be signed at the event. Enditem