Under the circumstances of economic globalization,the trade mode between the south and the north may cause "the shift of environment cost" from developed countnes to developing countries,which leads to "speaalization trap"in the trade structure in developing countries and makes sustainable economic development impossible.Hence,in order to implement sustainable economic development in China's western part,we should be on guard against"environmentae dumping"from developed countries and pay attenton to the shift of environment cost from China's eastern areas to its western areas.