The plant's operator Tokyo Electric Power Co (TEPCO) released 11,500 tonnes of low radioactive water into the sea earlier this week, after which Chinese officials believe that a number of Chinese cities started feeling the spread of radiation.
The Japanese side has informed China about the event and China "is naturally concerned" as a close neighbour, Foreign Ministry spokesman Hong Lei said.
Hong urged Japan to act in line with relative international laws and take substantial measures to protect the ocean environment, Xinhua reported.
China is closely watching the situation, conducting monitoring and keeping in contact with the Japanese side, Hong said.
He urged Japan to provide timely, comprehensive and accurate information to China.
Published 09 April 2011, 02:23 IST