Eastern costal regions in China ordered boats to shore and evacuated people on land to prepare for Typhoon Dujuan after it made landfall in Fujian province on Tuesday morning.
The typhoon had already left three dead and more than 300 injured in Taiwan.
The typhoon, the 21st this year, landed at the southeastern coastal city of Putian in Fujian province at 8:50 am on Tuesday, bringing torrential rain and gales to parts of Fujian and Zhejiang provinces and Shanghai.
It had been expected to move inland but became weakened and hit Jiangxi province on Monday night.
It was forecast to bring heavy rains for a few days, affecting people heading south during the holiday week from Thursday to Oct 7, the Central Meteorological Station said on Tuesday.
The typhoon hit the eastern coastal regions during the highest tide of the year, which would intensify its effect, said Wang Weiguo, senior engineer working at the Central Meteorological Station on Tuesday.
Two people in Taiwan were killed and another 324 people injured as the typhoon swept across the island after its landfall at 5:50 pm on Monday.
The National Marine Environmental Forecasting Center issued a red alert, the highest level, on Monday, ordering the affected regions to call boats back to harbors and evacuate people along the shore.
Fujian has since ordered over 30,000 fishing boats, carrying 160,000 people, to return to shore. Zhejiang evacuated more than 320,000 people from its coastal regions.
Another two tropical cyclones are due to hit the northwestern Pacific Ocean during Golden Week.
"In autumn, it's still possible to have devastating typhoons, so the coastal regions need to reinforce their efforts to prepare," Wang said.