Customers select products in a duty-free shopping mall in Haikou, south China's Hainan Province, Oct. 4, 2020. (Photo: Xinhua)

China's resort island province of Hainan raked in 1.04 billion yuan (about 155 million U.S. dollars) in duty-free sales during the National Day holiday, an increase of 148.7% year on year, according to customs authorities.

Data from Haikou Customs showed that Hainan's four offshore duty-free shops currently in operation received some 146,800 customers and sold 998,900 duty-free merchandise during the eight-day holiday that ended Thursday, up 43.9% and 97.2% year on year, respectively.

Hainan's tourism and culture department said more than 4.5 million tourists visited the tropical island during the holiday, with tourism revenue rising 26.6% year on year to 6.6 billion yuan.

Starting on July 1, Hainan increased its annual tax-free shopping quota from 30,000 yuan to 100,000 yuan per person.

The range of duty-free goods has also expanded from 38 categories to 45, while the previous tax-free limit of 8,000 yuan for a single product has been lifted.

From July 1 to Sept. 30, Hainan recorded 8.61 billion yuan of duty-free spending by visitors, a surge of 227.5% year on year, according to the General Administration of Customs.

China released a master plan in early June on building the southern island province into a globally influential free trade port.