2018 marks th 30th anniversary of the founding Hainan Province and Hainan Special Economic Zone.
China Post released 4 pre-stamped postal cards.
One card shows Wuzhi Shan, the highest mountain of Hainan.

China 2018 pre-stamped postal card Wuzhi Mountain Hainan
Wuzhi Mountain.

China 2018 pre-stamped postal card Sanya International Duty-free Mall
Sanya International Duty-free Mall.

China 2018 pre-stamped postal card Round the Island High Speed Railway
Round the Island High Speed Railway.

China 2018 pre-stamped postal card Wenchang Space Launch Center
Wenchang Space Launch Center.