reason is that Thailand offers tourists visas when they arrive. This makes it easier to plan a short trip because you don't need to get a visa before you leave home.
This year the Tourism Authority of Thailand expects that 15 percent of its 25 mollion tourists will come from mainland China. As well as the traditional tourist destinations such as Bangkok, pattaya, and phuket, the chinese often choose to visit Chiang mai. Why? Because Lost in Thailand
Thank, Xu Zheng!