Chinese new year fireworks：

http://www.chinesenewyear.me/chinese-new-year-fireworks.html

Chinese new year fireworks show 2011

Burning fireworks was once the most typical custom on the Spring Festival.
As is with most of the traditional practices of the country you will be able to hear a number of stories regarding the significance and origins of the fireworks tradition. A common belief is to make some noise so as to wake up a sleeping dragon. This dragon is believed to bring the rain during summer in order for the crops to grow.
In many western countries fireworks are let off at midnight, and many people like to make a noise, possibly to drive away bad spirits.

1. It reminds people of an old Chinese tradition
2. It hightens festival's exciting atmosphere
3. It increases retail business
4. It provides an entertainment for people