All visitors arriving in the People's Republic of China must complete a customs declaration form to present on arrival. One copy of this form should be retained, to hand in to customs on departure. Each traveler is permitted to bring in four hundred cigarettes, two liters of alcohol, twenty fluid ounces of perfume and up to fifty grams of gold or silver. The cash amount that visitors can legally bring in or take out is only RMB6000 and foreign currency over the value of US$5000 or equivalent. Any amount exceeded this limit must be declared. Certain valuable items, such as video cameras, office machines, computers and gold should have import duty paid on them. Prohibited imports include arms, ammunition and explosives; printed matter, film or tapes critical to the country; dangerous or narcotic drugs; infected animals, plants or foodstuffs. It is also forbidden to carry any of these items, or endangered species of animals or plants and antiques without export permits. You may be asked to present an official receipt for any cultural relics you plan to take out of the country. Generally speaking, customs don't hassle foreigners too much. There are green channels and red channels. If you have something to declare, take the red channel. Otherwise choose the green channel to clear Customs upon arrival in the People's Republic of China.