Thailand and China, two countries have a long relationship, because of Thai sent envoys to visit China, also China sent envoys to visit Thailand. After that, Thailand and China start to connect in Hun dynasty period and China have to history note about Thai people, then Thai people and Chinese people always to visit. Thailand and China have to many side relation they are society and culture, trade, have to befriend history, politics,tourism and lineage. Thai's product sent to sell in China around 86% and China's merchant ships entering. Thailand outnumbered all other foreign merchant ships in Thai ports. China had become Thailand’s major partner in foreign trade and most of merchant in Thailand is Chinese people. Then, Chinese people immigrant came to live in Thailand, and Chinese people married with Thai people and thus it makes Thailand to get Chinese cultural. We can observe from Thai people having Chinese lineage and most of festival in Thailand like a Chinese. Frequent of country’s leader, it makes two countries, deepening the friendship between China and Thailand. After the Second World War, Thailand and China signed the Siam-China Friendship Treaty. Now, we look to tourism is Chinese people more than other country come to travel in Thailand,and most of student in Thailand study Thinese language, because the ancient times Chinese people came to live in Thailand, then the Chinese people teach Chinese language to Thai people. It make we know Thai and China have to good relation so long time more than other country.