I don't agree with the other answers, but as the question is been closed so I can only write my answer here. 盈余 and 顺差 is totally two different things. 盈余 is for one country or company itself, it earns money instead of losing money. If we are talking about 盈余, we only talk about the country or company itself, we don't care it earns money or lose money from which country or company, but in total, it earns money. But 顺差 is between two countries (we don't usually use it between companies), for country A, if the value of export to country B is larger than the value of import from B, then we say country A has a 贸易顺差 to country B. At the same time, B has a 贸易逆差 to A, because obviously at this time, the value of import of B from A will be larger than the value of export from B to A. Is it clear?

We usually use '盈余' and '赤字' when we say surplus and deficit of cashflow . '贸易盈余'' is equal to''贸易顺差'' . '贸易赤字'is eaual to .''贸易逆差''. '贸易盈利' sounds weird. '盈利'is usually used in the running of a company.

贸易顺差。， 至于赤字和黑字，虽然赤的反义词是黑，但是一般我们把“黑字”称作财政盈余。 http://zhidao.baidu.com/question/6100423.html 以下可以解决你的问题。