Nearly one-million people have been evacuated from the coastal regions of China which are being battered by Typhoon Morakot.
Winds of up 119km/h (74mph) destroyed houses and flooded farmland.
Flights were cancelled and fishing boats recalled to shore. A small boy died when a building collapsed.
Meanwhile, in Japan nine people are reported dead in floods and landslides after Typhoon Etau brought heavy rain to the west of the country.
Eight people died in Hyogo prefecture, including one man whose car was swept away by a swollen river, and another died in neighbouring Okayama prefecture.
Another 10 people are missing.
Chinese state media said that the sky turned completely dark in Beibi, Fujian, when Typhoon Morakot made landfall on Sunday morning.
Trees were uprooted as high winds and heavy rain lashed the coast.
Some 473,000 residents of Zhejiang province were evacuated before the typhoon struck, as well as 480,000 from Fujian, Xinhua news agency said.
In Zhejiang's Wenzhou City a four year-old child was killed when a house collapsed. Dozens of roads were said to be flooded and the city's airport was closed.
Rescuers used dinghies to reach worst-hit areas; in one area only the tops of trees were said to be showing above the floodwater.
Earlier, Morakot dumped 250cm of rain on Taiwan as it crossed the island, washing away bridges and roads.
At least three people died in some of the worst flooding for 50 years.
In one incident, an entire hotel - empty at the time - was swept away by the waters.
At least three people were known to have died - a woman whose car went into a ditch and two men who drowned.
Thirty-one others were reported missing, Taiwan's Disaster Relief Centre said. Among them were a group reportedly washed away from a make-shift shelter in Kaohsiung in the south.
At least 10,000 people were trapped in three coastal towns, a local official in the southern county of Pingtung said.
In Chihpen, one of Taiwan's most famous hot spring resorts, a hotel collapsed after flood waters undermined its foundations.
Morakot - which means emerald in Thai - has also contributed to heavy rains in the Philippines. At least 10 people were killed in flooding and landslides in the north.
Typhoons are frequent in the region between July and September.