The almost 9,000-km-long railway connects Inner Mongolia to the city of Bam in southeastern Iran and will be used by cargo and service trains, IRNA reported.
In the opening ceremony of the new railway, a cargo train moved from Inner Mongolia logistic and industrial town to the city of Bam. It is estimated to arrive in Bam in 15 days.
The train consists of 41 containers carrying equipment, machineries and car spare parts.
The consignment worth is $1.5 million.
In another development, a cargo train left the city of Bayannur in western Inner Mongolia for the Iranian capital city of Tehran.
The two railways are part of a larger rail network which is to connect China to the Europe via Iran.
The railways have been launched since March 2011 and been used by almost 10,000 cargo trains.