The 2,298-kilometer-long (1,428-mile-long) line between the Chinese capital and the country's major commercial center in the south, formerly called Canton, spans more than half of the country and cements the country's high-speed railway development ambitions, China's official Xinhua News Agency reported.
The rail route has four main sections, running between Beijing and the central transport hub Zhengzhou in Henan province, and then to Wuhan in central China, and on to Guangzhou.
The Xinhua report was accompanied by spectacular color photographs of the gleaming, luxury trains running on the line. Guangzhou is the capital of Guangdong province and is just north of Hong Kong.
The news agency said two trains departed from stations in Beijing and Guangzhou in the morning, traveling at average speeds of 186 mph, to mark the opening of the line, which will have 35 stops in major cities and eventually will operate 155 trains daily.
"The opening of the Beijing-Guangzhou high-speed line shows that China's high-speed railway network has started to take shape," said Zhou Li, director general of science and technology at the Ministry of Railways.
Xinhua said with the opening of the new line, China will have more than 9,300 kilometer (5,778 miles) of high-speed rails in operation. The target is to have four east-west lines and four north-south lines with total operating lines of more than 120,000 kilometers (74,565 miles) by 2020, Xinhua said.
Another major north-south route connecting Beijing and Shanghai opened in June 2011.
The high-speed rail effort sustained a huge setback in July 2011 when an accident killed 40 people, raising doubts about its safety and exorbitant cost, and resulting in the program's slowdown. The program has since picked up following a comprehensive safety review. Train speeds, however, have been reduced from 350 kilometers per hour (217.5 mph) to 300 kilometers.
Officials said many suspended projects have resumed construction. The Ministry of Railways has been allotted $96 billion for next year's rail infrastructure.
"High-speed rail construction needs government funding. The loans the ministry borrowed have accumulated to nearly 4 trillion yuan [$641.63 billion] so far, and each year the ministry needs to pay 80 billion yuan [$12.83 billion] in interest," one official said.