Sanya's headline shopping experience is the Sanya International Duty Free Mall in Haitang Bay — the largest duty-free complex in the world, and the main reason many domestic tourists fly to Hainan in the first place. Anyone who has flown into Hainan from elsewhere in China or abroad is eligible to buy here at duty-free prices, up to a generous annual limit. The mall stocks the major luxury cosmetic, watch, handbag, electronics, and liquor brands; same-day pickup at the airport is standard.
Beyond duty-free, Sanya is known for seawater pearls, which are a genuine local speciality. Buy from established shops like GN Pearl or Heren Pearl rather than beach vendors, where fakes are common. Tropical fruit is sold all over the city — mangoes, dragonfruit, jackfruit, durian, lychees, longans, wampee — and is generally cheaper and better than what you'd find on the mainland. The First Market in central Sanya is the place to buy fruit by the kilo; the Wanghao supermarket chain is convenient for packaged goods.
A note of caution: coral products are sold openly in souvenir shops but their export is illegal under Chinese and international law, and customs will confiscate them. Don't buy. Tortoise-shell ornaments fall in the same category.
For everyday shopping, the centre of the city has several large malls including the Summer Mall and the Yifang Department Store. Hongqi Shopping Street is the local pedestrian strip for budget clothes and souvenirs.