The Chinese government continued implementation of the strategy of “The Belt and Road”. The strategy has brought new opportunities for China and South Asia economic and trade cooperation. According to the “UN” UN-COMTRADE database, measuring the trade of China and South Asia of each index, revealed comparative advantage index, export similarity index, the specialization of the revised coefficient and coefficient of consistent indices, analysis competitive and complementary of China and south Asian countries trade. Results show that the trade structure of China and South Asia has a certain competitiveness, but also has a lot of complementarity. There are lots of varieties for trade. Chinese exports to South Asia have a wide range of categories, export manufactured goods are the main products. South Asian exports to China are the low value-added primary products and semi-finished products mainly. Under the background of the strategy of “The Belt and Road”, policy measures should be taken to promote China’s economic and trade relations with south Asian countries.