Trains on China's high-speed rail network are designed to travel up to 350 kmph, but Beijing ordered speeds to be cut to between 250-300 kmph in 2011 after over 30 people were killed in a train crash in eastern Zhejiang province.
The Beijing News said the government planned to implement the increased speeds between Beijing and Shanghai in September, which would cut travel time to 4.5 hours from up to 6 hours currently.
China's newest "Fuxing" bullet trains, which were unveiled in June and are capable of top speeds of 400 kmph, will be used for that journey, it said.
China is home to the world's longest high-speed rail network which competes heavily with domestic airlines. Of China's 31 provinces and regions, 29 are served by high-speed rail with only the regions of Tibet and Ningxia in the northwest yet to be connected.