Chinese state media said a man stabbed eight people to death including his mother, wife and daughter.
The official Xinhua News Agency cited police as saying the stabbings were yesterday night in the southeastern province of Jiangxi.
The report said four neighbours and a migrant worker were also stabbed to death.
Xinhua cited police in Jishui county as saying suspect Zhou Yezhong was caught within two hours of the stabbings.
China has been shaken in recent weeks by multiple cases of mass violence, including attacks on schools.
Some were blamed on the mental illness of the attacker and others were blamed on the pressures of a rapidly changing society.