Megi, the 17th typhoon this year, brought downpours to the coastal areas of the Fujian province.
Four counties and one city in Fujian saw more than 300 mm precipitation, while the precipitation in 15 counties, districts and cities was between 200 and 300 mm, said the provincial flood control office.
The water level of local rivers surpassed alert levels. China has already issued an orange alert for Megi.
Fuzhou, the provincial capital, was also battered by rainstorms. The city's roads and streets were waterlogged, affecting traffic.
In Taiwan, it killed four people and injured 268 others as it travelled across the island yesterday, state-run Xinhua news agency reported.
Last week, Meranti, the strongest typhoon to hit China this year, killed at least ten people in Zhejiang, with most casualties being caused by landslides and flash floods in rural areas.