If you google "英语摘要的时态，" you will see "use the past tense." (网上搜索，你会看到“摘要应该用过去时”。）

If you never wrote a paper on your own, you may take this as the truth and follow it faithfully.

But, I have to say this "rule" needs to be relaxed. Here is why. （但是，摘要不一定非用过去时哦。）

I am an ocean modeler, and used to write papers on basic physics related to ocean dynamics. I never used the past tense in my own abstracts, never. Instead, I used the present tense. (Oh, in case you don't know my work, all my papers were published in good journals in the field.) Why? This is because these papers are about basic physics, and the results remain true if one repeats these numerical experiments (at least I hope so :)

So, now you know at least there are two ways to write an abstract: the past tense, and the present tense. （摘要可以用过去时，也可用现在时。）

In fact, you cannot use the past tense if you want to end the abstract like this: "This new method has great potenial in xxx application." (有时你不能用过去时，比如谈论一个新方法的应用。）

The best way to decide which tense to use is to read your colleagues' papers and to check out journal's requirements (under guidelines for authors).（最好的办法是看看你的同行怎么写摘要、看看期刊是怎么要求的。）

One more thing, to end the abstract with the potential impact of some of your new findings, you have to use the present tense, I think. (Now, you see where I stand.) （显然，有时你只能用现在时。）

For example: This new method may have potential application in identifying new species.

I also find this link useful for Chinese authors:

http://www.xuebao.tyut.edu.cn/webpage/EI.htm