As a crux in US-China bilateral trade relationship，US’ deficit has been shaped and enlarged by a combination of the factors including international industrial transfer，the two countries’ different savings rate and etc. US’s budget deficit policy promoted through the dominance position of US dollar，serves as the essential reason for trade deficit of US in the bilateral trade. The report argued that US has gained the maximum benefits through the global trade imbalance which reflected by US’s deficit. In the long run，however，it is difficult for the US dollar credit to sustain continuously the increasing trade deficit of US.