BEIJING, Dec. 11 (Xinhua) -- China has scaled up investment in railway construction since the beginning of the year, data from the country's railway operator showed Monday.

During the January-November period, the fixed-asset investment in the country's railway sector reached 640.7 billion yuan (about 90 billion U.S. dollars), marking a 7.4 percent increase from the previous year, according to China State Railway Group Co., Ltd.

As of the end of November, the total operation mileage of China's railway network exceeded 155,500 km, including 43,700 km of high-speed railways.

Latest progress in the country's rail infrastructure construction include the completion and operation of a high-speed railway connecting Jinan, capital city of eastern Shandong Province, and Zhengzhou, a transportation hub in the central.

The company said maintaining the investment at a high level is vital to further improving China's modern rail network and boosting the overall economic and social development.