As we all know the keywords in seo play an important role. And there are two main keywords -target keywords and long tail keywords. Target keywords are used by target customers for making more a good rankings in search engine. Also, most of the traffic are from target keywords. While long tail keywords are the non-target keywords which can bring search traffic to websites. They have several main features. One is long. They are usually make of two or three words, even short phrases. Then they not only appear on the internal content, but also appear in the web tittle. Also the search rate is rarely low and not stable in some aspects. Most of the customers brought by the long tail keywords can become into target customers, and the success rate is higher than that of target keywords.