The line officially opened today when a train left from Beijing at 9am local time. Another train left Guangzhou for Beijing an hour later.
Trains on this high-speed line will initially run at just over 300 kph (186 miles per hour) with a total travel time of about eight hours.
Before today, the fastest time between the two cities by train was more than 20 hours.
Railway is an essential part in China's transportation system, and its government plans to build a grid of high-speed railways with four east-west lines and four north-south lines by 2020.