The 6-ton vessel Jin Tian was manned by a crew from China and Myanmar. Only five of the 13 found have survived, Chinese media reported.
A cargo ship that sank off the coast of Japan on Tuesday, amid poor weather conditions, has left eight people dead according to Chinese media. Six of the dead were Chinese nationals, a government official told state broadcaster CGTN on Thursday.
The incident took place some 110 kilometers (68 miles) west of the remote and uninhabited Danjo Islands in southwestern Japan. The ship named Jin Tian, had a crew members from China and Myanmar.
The 6,651-tonne vessel was registered in Hong Kong, Japan's coast guard said.
Crew forced to abandon ship
The ship's captain sent a distress signal to South Korea's coast guard on Tuesday evening, saying the crew would abandon ship. The vessel then sank at approximately 2:46 am local time (5:46 pm UTC on Tuesday).
No immediate cause for the sinking has been determined, but a South Korean coast guard spokesperson said the area was experiencing strong winds at the time of the incident.
A cold snap hit much of Asia this week, with daytime temperatures in some Japanese islands nearest the rescue site reaching just 3 degrees Celsius (37 degrees Fahrenheit).
Hundreds of flights to South Korea's Jeju island were canceled on Tuesday due to extreme weather.
Search teams find survivors
Some 13 crew members were rescued from the scene, with Japan's coast guard and military, and also three private ships from the area, joining in the search.
China's Consul General in the Japanese city of Fukuoka, Lu Guijun, told Chinese media that of those rescued, five individuals had non-life-threatening conditions.
"We express our deepest condolences to the unfortunate victims," Lu said of the remaining eight crew members who perished.
China's ambassador to Japan, Kong Xuanyou, visited the survivors and provided them with clothes, food and drink.