很多SEO初学者依然会探究一个问题，keywords标签对于网站关键词排名是否有作用呢？今天我们就一起来研究这个问题，让大家得到更确切的答案，明白keywords标签是否还有作用。
首先Google的Matt Cutts在博客上发表了文章，宣布Keywords标签对Google的排名基本没有影响了，而且也不会再作为排名的因素。下面是文章的内容：
Recently we received some questions about how Google uses (or more accurately, doesn’t use) the “keywords” meta tag in ranking web search results. Suppose you have two website owners, Alice and Bob. Alice runs a company called AliceCo and Bob runs BobCo. One day while looking at Bob’s site, Alice notices that Bob has copied some of the words that she uses in her “keywords” meta tag. Even more interesting, Bob has added the words “AliceCo” to his “keywords” meta tag. Should Alice be concerned?
At least for Google’s web search results currently (September 2009), the answer is no. Google doesn’t use the “keywords” meta tag in our web search ranking. This video explains more, or see the questions below.
Q: Does Google ever use the “keywords” meta tag in its web search ranking?
A: In a word, no. Google does sell a Google Search Appliance, and that product has the ability to match meta tags, which could include the keywords meta tag. But that’s an enterprise search appliance that is completely separate from our main web search. Our web search (the well-known search at Google.com that hundreds of millions of people use each day) disregards keyword metatags completely. They simply don’t have any effect in our search ranking at present.
Q: Why doesn’t Google use the keywords meta tag?
A: About a decade ago, search engines judged pages only on the content of web pages, not any so-called “off-page” factors such as the links pointing to a web page. In those days, keyword meta tags quickly became an area where someone could stuff often-irrelevant keywords without typical visitors ever seeing those keywords. Because the keywords meta tag was so often abused, many years ago Google began disregarding the keywords meta tag.
Q: Does this mean that Google ignores all meta tags?
A: No, Google does support several other meta tags. This meta tags page documents more info on several meta tags that we do use. For example, we do sometimes use the “description” meta tag as the text for our search results snippets, as this screenshot shows:
Even though we sometimes use the description meta tag for the snippets we show, we still don’t use the description meta tag in our ranking.
Q: Does this mean that Google will always ignore the keywords meta tag?
A: It’s possible that Google could use this information in the future, but it’s unlikely. Google has ignored the keywords meta tag for years and currently we see no need to change that policy.
大概内容是跟我们说明Google已经不再把keywords标签作为关键词排名的因素，因为太多人滥用keywords标签导致Google决定忽视这个标签，但是这样并不意味着Google会忽视其他meta标签，而且Google预计会一直忽视keywords标签，至少目前Google没有必要去改变这一政策。
所以也确切地证实了keywords标签对于Google排名着实已经没有作用了，那么对于百度、Yahoo这两个比较重要的搜索引擎是否还有作用呢？
下面请大家先看ZAC做的具体实践证明：
在网站的keywords tag中加上了这么一段 – “伍疗踢瓜sdfghj”。然后观察这个词（就当是个词吧，不然也不知道怎么说）在搜索引擎的排名情况。这个词在我加在首页之前，在百度，Google，Yahoo都没有任何结果。
查看的结果是，百度还是没有任何结果，说明百度完全忽略keywords tag。
用“伍疗踢瓜sdfghj site:chinamyhosting.com”在google查也没有任何结果：
说明Google也完全忽略关键词标签。
在Yahoo搜一下，结果就不同了：
显然，Yahoo不仅记录keywords标签，还用于排名。
后来Yahoo又有人解释说，keywords标签给的权重是最低的，页面其他任何地方出现关键词也比在keywords标签里出现强。只有在没有其他页面包含关键词时，keywords标签里的词才会起作用。
还好我同时还做了另一个测试，在keywords标签还加了“黄飞鱼大闹天宫”这么一句。这个词在我加上时在三个搜索引擎就有匹配页面出现，当然，数目很少。现在在百度和Google搜索“黄飞鱼大闹天宫”，我找不到本站的首页，符合预期。
在Yahoo里又不一样了：
只在keywords标签出现关键词的页面排在第二了，超过一些可见文字中含有关键词的页面。
所以，Yahoo不但考虑keywords标签，权重还不像他们自己说的是最低最低那种。
总的来说，还是建议大家在网站上添加keywords标签，带上网站的2-3个目标关键词就可以，堆叠关键词就显得很没必要了！
