Yunnan Province, as one of China's southern provinces, has extensive trade partners with more than 130 countries and regions, among which ASEAN is the biggest one. Yunnan-ASEAN trade volume covers over one-third of Yunnan's total trade volume. The trade interactions between Yunnan and ASEAN countries are greatly promoted by regional preferential customs agreements, such as Early Harvest Program (EHP) and Special Preferential Tariff Treatment to Cambodia, Laos and Myanmar. The trade volume doubled from US$ 1.12 billion in 2003 to US$ 2.17 billion in 2006, increasing by 28.9% annually.