The visit coincides with an all-expenses paid trip to Boryeong City in South Korea after the two cities signed an events partnership agreement in June last year.
Rotorua's new Mudtopia festival is based on the South Korean city's Mud Festival and Mrs Chadwick has also been invited to be a keynote speaker at a tourism symposium in Incheon.
Councillor Rob Kent, who voted against the proposal, questioned the necessity for overseas travel by elected officials.
"I'm not convinced it actually achieves anything at all other than joy-riding at ratepayer expense, but you can prove me wrong."
He suggested Rotorua's Chinese Community of Commerce could cover the costs, instead of ratepayers.
Councillor Peter Bentley said he was afraid Rotorua community would see the trip as a junket.
But councillor Mark Gould said New Zealand's closer ties to China should be supported and the mayor's visit would attract media attention and promote the district as a visitor destination.
Councillor Karen Hunt said calling the trip a junket was "naive and patronising" and said it was a significant, international and prestigious invitation and no dollar value could be put on such a visit for the profile of Rotorua.