The Ministry of Civil Affairs issued a circular on Friday, ordering Fujian, Guangdong and Zhejiang Provinces to prepare for the typhoon and disaster relief work. A working group of the ministry has gone to Fujian to guide and help local governments.
The ministry also ordered Anhui, Jiangxi and Hunan Provinces to monitor Sepat as they might also be affected.
The Fujian provincial meteorological station said on Friday that Sepat could make a landfall on Saturday evening or Sunday morning, bringing strong winds and torrential rain.
The typhoon, which has weakened slightly, is packing winds of 198 kilometers per hour. It was located at 21.3 degrees north and 123.3 degrees east at 4:00 pm on Friday and heading northwestward at 20 kilometers per hour.
Sepat was expected to make landfall in Taiwan early Saturday, before crossing the Taiwan Strait to Fujian.
Winds along the coast would gain strength on Friday evening and might exceed 160 km per hour on Saturday and Sunday, while rain is forecast to pound Fujian and neighboring Guangdong and Zhejiang provinces.
Warnings have been issued in the provinces for fishing boats to return to harbour and to ensure villagers are on the alert for landslides.
In Fujian, all vessels were ordered to return to harbor by midnight. By 6:30 pm on Friday, nearly 10,000 ships and 36,000 maritime workers fishermen had returned.
Passenger liners shuttling from Fujian to Taiwan have been suspended since Friday afternoon and it is undecided when services will resume.
It was raining and blowing in Fuqing, a coast city of Fujian, on Friday. A town government head told Xinhua that 490 people whose homes were in danger had been relocated.
In Zhejiang, more than 3,500 fishing boats and trawlers carrying 9,000 fishermen have sought shelter. Twenty five rescue groups with nearly 300 people and 135 ships are on stand-by.
Marine traffic has been suspended by Friday evening on the seas near Zhejiang.
In Guangdong and Fujian, more than 14 million short messages have been sent to mobile phone users, warning them of severe weather.
Sepat, named after a Malaysian freshwater fish, is the ninth tropical storm to hit the region. Formed early on Monday east of Luzon island in the Philippines, it became a super typhoon at around 8:00 pm on Wednesday.