On Thursday, Fukushima’s operator, TEPCO, started dumping the treated wastewater from the plant into the Pacific Ocean, having diluted it with sea water in advance.
"It is extremely selfish and irresponsible behavior to openly expose the whole world to the risk of radioactive contamination," Wang told a briefing.
The diplomat urged Japan to "immediately change its selfish behavior" and prevent this situation from turning into a "disgrace for Japan."
China and other nations are entitled to take legitimate preventive measures to ensure the security of the marine environment and people's health in response to the "irresponsible actions" of Japan, Wang added.
On Thursday, the Chinese customs authorities announced the suspension of all seafood imports from Japan in response to the start of the treated radioactive water release.
Tokyo said earlier in the year that it had to discharge the treated water as it urgently needed to free up space at the disabled nuclear facility. The water has been purified of all radionuclides except tritium. The move faced criticism from a number of countries, including China, South Korea and North Korea, who fear radioactive contamination. The International Atomic Energy Agency said that Tokyo's activities were consistent with international safety standards and that treated wastewater would have a negligible radiological impact on people and the environment.
In March 2011, three of the Fukushima nuclear plant's reactors melt down after the nation was struck by a magnitude 9 earthquake followed by a massive tsunami. Fukushima is considered the worst nuclear catastrophe since the Chernobyl disaster in 1986.