Six of the world's 20 fastest-growing destination cities are in China, and the country's lesser-known cities including Harbin are becoming more popular with tourists, are the two key findings of a new tourism industry spending survey from Mastercard Inc.

Harbin was ranked first in MasterCard's survey of 132 cities, and along with Xi'an, Guangzhou and Chengdu, make up four of the 10 fastest-growing vacation destinations by traveler spending, ahead of Tokyo.

Tourism receipts in Harbin are projected to rise 53 percent this year, the report showed.

Increased air connectivity within the Chinese mainland and outside, coupled with advertising efforts by city officials, have made tourists more aware of these previously obscure cities, Yuwa Hedrick-Wong, a MasterCard economic adviser and author of the report, said at a briefing in Singapore on Monday.

Six of the world's 20 fastest-growing destination cities are in China, the credit-card company's report showed, including Guangzhou and Qingdao.

Spending in Tokyo is expected to rise 24 percent, while Istanbul may climb 21 percent, according to the report.