Setting off firecrackers is one of the most popular customs in the Spring Festival celebration. The crackles of firecrackers will burst reverberating across the heavens the moment the clock strikes twelve on New Year's Eve. Firecrackers are also set off when people pay New Year calls and offer New Year sacrifices to their ancestors. The firecracker is also known as the bamboo-cracker, which is linked with a tale. According to Shen Yi Jing( Classic of Rare Gods)by Dongfang Shuo( 154-93B. C.)，a writer in the Western Han Dynasty,a group of odd people,a little more than a feet tall,lived in the high mountains of west China in ancient times. Naked,they lived on shrimps and crabs and often stole salt from villagers' houses to spice their food. These odd people would make villagers run a fever if the latter encountered them. They feared nothing but the crackles produced by burning bamboo tubes. Hence villagers resorted to burning bamboo tubes to threaten them away. Thinking the way magical，later people burned bamboo tubes on New Year's Eve, supposed to exorcise all evil spirits. In the Song Dynasty people began to set off firecrackers filled with gunpowder, instead of burning bamboo tubes,on New Year's Eve. Now,firecrackers are set off more for heightening the festive air than for the original purpose.