LANZHOU, July 5 (Xinhua) -- The 24th China Lanzhou Investment and Trade Fair opened Thursday in Lanzhou, capital of northwestern province of Gansu, with a theme of green development along the Silk Road.

This year's fair will promote cooperation in efficient use of energy, environmental protection, clean production and sustainable agriculture.

The fair will run from July 5 to 9 with guests from more than 40 countries and regions.

The Lanzhou Fair was first held in 1993 and is an important platform for opening up in northwest China. It has grown in importance as China accelerates opening-up to central and west Asia under the Belt and Road Initiative.