The 25-year-old suspect, surnamed Ou from central China's Hunan Province, was caught this morning, police said.
He has confessed to the violent act and is currently in police custody, state-run Xinhua news agency reported.
It was not yet clear why the man resorted to carry out the bomb attack on the passenger bus in south China's Guangdong province last night.
Eyewitness said a man placed the bomb near the door of the bus and fled.
Most of the victims suffered burn injuries. They are treated at three hospitals in the city.
The explosion took place near Guangzhou Avenue, a busy road linking the northern and southern parts of the city.