From next week, some of the trains will once again be allowed to run at a higher speed of about 350 km/h.
The higher maximum speed should cut about an hour off the journey time between Beijing and Shanghai.
The top speed of the Fuxing or “rejuvenation” bullet trains was capped at 300km/h (186mph) in 2011 following two crashes that killed 40 people.
To mark the return of the higher-speed service, the trains have been named “Fuxing” – Chinese for rejuvenation – in line with a national government slogan and development plan.
By 21 September, seven of China’s bullet trains will be permitted to travel at the increased maximum speed.
The nation’s rail operator is believed to be looking into ways to upgrade track to let the engines run even faster – perhaps at speeds approaching 400km/h. China is believed to have about 19,960km (12,400 miles) of high-speed rail tracks.