XINING, May 7 (Xinhua) -- More than 49 million people have traveled on the Qinghai-Tibet railway, the world's highest, since the route opened in July 2006, the railway company said Monday.

Passengers on the Qinghai-Tibet railway have increased on average 10.3 percent annually, said Wang Tao, spokesman with the Xining-based Qinghai-Tibet Railway Company.

The number of passengers taking the train has increased from 6.4 million in 2006 to 10 million in 2011, said Wang.

The high-elevation railway that connects Xining, capital of Qinghai province, to Tibet's capital Lhasa, also transported 40 million tonnes of cargo in 2011, up 8 percent year-on-year.

Tourism in Tibet autonomous region in southwestern China has boomed since the 1,956-km railway went into operation six years ago. In 2011, a total of 8.6 million tourists visited Tibet.

By the end of the 2011-2015 period, it is expected that Tibet and Qinghai will receive annual tourist arrivals of 15 and 20 million respectively.