China issued "strong dissatisfaction" with Japan for approving the Falungong spiritual group as a non-profit organisation, comparing it to the Aum Supreme Truth doomsday cult.
Falungong, known as the Japan Falun Dafa Society in Japan, "is of the same nature as the Aum Supreme Truth cult", the Chinese embassy in Japan said, referring to the group that spread deadly Sarin nerve gas in the Tokyo subway in 1995, killing 12 people.
It said Falungong, outlawed as an "evil cult" by China since 1999, had a "stinky reputation" around the world.
"They have complete spiritual control of their followers," the embassy said in a statement on its website.
"They have seriously harmed society's order as well as people's lives."
Tokyo's approval of Falungong as a non-profit organisation was "against the wish of Chinese people in Japan and the Japanese people", it said.
Falungong once claimed millions of followers on the mainland but has faced a tough crackdown by the government, which considers it one of the most serious threats to its rule.
The group claims that at least 1,600 of its members have been tortured or beaten to death in China since a crackdown ordered four years ago largely drove the organisation underground.