In a context of growing liberalization, the trade of agricultural biotechnologies represents an opportunity for economic « catch-up » for emerging countries that have opened their economies and that are integrated into the world markets. Moreover, cooperating in the field of biotechnological innovation gives them a potential room for manoeuvre when coping with western powers. However, the regulatory confusion regarding this area poses a threat to South-South cooperation in making this innovation and its first fruits a strategic tool. Considering an alternative theoretical approach of power applied to the Sino-Brazilian partnership, this article focuses on the agribusiness sector and on the transgenic soya case in order to understand how China is building an asymmetrical interdependence between the Brazilian agricultural leader and the Chinese challenger.