Europeans had been trading with China since the early 1500’s, the early traders involved with China include the Portuguese and Dutch. The Portuguese were the first to reach China in 1514. By 1557, the Chinese government grants the Portuguese trading peninsula of Macao. The Portuguese established themselves as major actors in the carrying trade, or exchange of goods between Asian countries and became involved in trade with China and Japan.
China had fallen behind other nations by the beginning of the 19th century, so this meant that the population didn’t have enough money to find food to feed their families. The Qing Emperors continued to follow old age traditions, the Qing Emperors were reluctant to change because China regarded itself as the Zhong guo (which meant the Centre of the World) and they wanted to deal with foreigners within the age old tribute system. Under the system anyone who wanted to trade with China had to acknowledge the superiority of the Emperor. Foreign mission members were required to kowtow when meeting the Emperor, this was a ceremonial bow, involving kneeling three times, tapping the forehead on the ground nine times and lying flat on the floor.
the following information is from my year 9 history text book , http://www.oxforddigital.com.au