There were fears the toll could rise as scores of homes were flooded in an area where more than 1 million people had to be evacuated.
On Thursday, officials said twenty-seven Vietnamese fishermen were missing after three boats went down in Chinese waters after being swept up in the storm.
A coast guard official from Vietnam's central Quang Ngai province said another 67 on six other boats safely reached an island. Vietnam asked China to help search for the missing.
Chanchu was the most severe typhoon to strike the South China Sea region during May and already was blamed for 37 deaths and the destruction of thousands of homes in the Philippines last weekend. It was downgraded to a severe tropical storm after hitting the coast of China early on Thursday.
The official Xinhua news agency said 11 people had died in China from the storm and four others were missing but gave no details. Earlier reports said eight people were killed, including two children whose houses collapsed, when the storm made landfall near Shantou in the northern tip of China's Guangdong province.
Taiwan reported the deaths of two women in the southern region of Pingtung who were swept away by floods brought on by the typhoon.
Police officers blow up buoys in a
drill to prepare for Chanchu
China said just over 1 million people have been moved to safety in Guangdong and Fujian provinces just to the north, a number that grew through the day. The storm bypassed the financial center of Hong Kong.
Thousands of people evacuated from fishing boats and low-lying areas were staying with relatives, in tents, or in schools and government warehouses, said a regional government official.
Television news showed waves pounding sea walls along the Chinese coast. Reports said winds and rain damaged dikes, uprooted trees and brought down buildings.
The storm flooded 192 homes and cut electricity in the Shantou area overnight on Wednesday before moving north into Fujian province before dawn, Xinhua said.
A Taiwanese helicopter lifts a crew
member from a freighter
The China Meteorological Administration's website indicated the storm would head out to sea on Friday morning.
Many scientists say they see a link between increasingly severe storms such as Hurricane Katrina, which battered New Orleans last year, and rising global temperatures.
The UN says the incidence of storms in the Western Pacific region rose by about 2% from the early 1980s to the late 1990s. Last year, a record 10 typhoons and tropical storms struck Japan, leaving nearly 220 people dead or missing - the largest casualty toll since 1983.