The most amazing fact is that it changes into one of the 4 largest cities in mainland China from a small fish village within 20 years. Shenzhen was a small fish village before 1980s, which located immediately north of HongKong(refer to HiChina guide book HongKong). After the “Reform and Opening” policy, Shenzhen was selected as a Special Economic Zone in August 1980, which change the command economy into market economy in this city, thus made the city boom in economy and population. Now Shenzhen is one of the 4 largest city in mainland China. Although located in Guangdong province, but as the 80% of population are immigrants from other provinces of China, the Mandarin is widely used in Shenzhen. The currency is CNY. All the laws of Peoples Republic of China are applicable in Shenzhen.