Abstract: This paper sets forth the intension of drug with the viewpoints of underground economics and economic geography.It points out that unlawful production and trade of drug in China not only affects the development of personal economy,but also damages public law and order.It also points out that there are two kinds of drug production base:domestic and abroad,and the latter is the major base for China.Both historical root and present driving force are the causes of the spatial diffusion of drug in China.The social problems and hideous phenomena arise from drug diffusion make the situation of banning drug very serious.How to cut off the source of drug and control the spatial diffusion of drug is a significant strategic problem for Chinese government.

Key words: China, drug, source, spatial diffusion