Experts say these railways will carry minerals and other cargo between China and Monglia to a network of Euroasian routeways.
Chinese Premier Wen Jiabao started his visit to Mongolia Tuesday, the third leg of his four-nation Asia tour. Wen is the first Chinese premier to visit Mongolia in 16 years.
Wen is scheduled to attend a trade cooperation forum, and agreements on finance, energy resources, science and technology, and infrastructure are expected to be concluded.
The total length of railways of Inner Mongolia will reach more than 15,000 km by 2015, with a total annual capacity of 900 million tonnes, according to meeting minutes signed between the Ministry of Railways and the government of Inner Mongolia Autonomous Region.
"This will lift China-Mongolia trade to a new level," said Erenhot City Mayor Meng Xiandong.