The cargo ship had 15 people on board when it sank at around 4:30 am (2030 GMT Tuesday), 90 nautical miles (167 kilometres) east of Taizhou City in Zhejiang province, Xinhua said, citing local maritime authorities.
The 80-metre (262-foot) long freighter departed the Taiwanese port of Kaohsiung with 14 crew members from Myanmar and one Taiwanese national. Four people have been rescued so far, Xinhua said.