Why Google changed SERPs' title tags of my webpages?

Hi gurus,my site was built in 2012,and did not have any good ranking,last year,in November 2015,I changed most of the comments,banner,URLs,title tags of most pages except for homepage,change a word,re-designed the whole website,and changing hosting as well,from then on,I began to buy SEO service from a famous forum, the SEO campaign was operated near one year.
Used this service I tried to rank the keywords:KA,all my keywords are:KA,KB,KC,KD,after serveral months,I found the serps of most of URLs have been changed their title tags,such as following:


The origianl title tags are:KB detailed informationm,KC detailed information,KD detailed information,after the SEO service,they were changed in SERPs as:
KB detailed information-KA,
KC detailed information-KA,
KD detailed information-KA


How can I resume the SERP title tags to the original ones?

strange, if you are using WordPress you can install Yoast it will help you to get the correct titles in Google and make you aware of any "seo mistakes" you may have done.

Just install any seo plugin such as yoast and make appropriate changes.

Remember, Google is not obligated to do anything you want. Often, they'll pick different peices of text to show in descriptions that they deem to be a better match or more suitable. That said, your article title (H1 tag) should appear as is. As others have mentioned, try a plugin like 'yoast' or 'allinoneseo'. Also, manually check your tag attributes.

Thanks a lot but my site is not wordpress,so can not be installed in the plugin you mentioned on the above.

Talking about the title tags, google added the keyword "KA" at the end of the title tags of SERPs, the KA was ranked by SEO service then which had to be builed as the anchor text of the link building, is this the real reason? Change words, my keyword ranking strategy was wrong?

If there are some SEO mistakes, then It may happen... You can install some of the tools, So that you can get an idea about it.. Yoast is also good tool for it..

In contrast to common believe, title tags aren't something Google always uses 1:1 for the SERPs. For example, without a NOODP tag Google may decide to use the DMOZ description if it seems to fit better in Google's opinion. Even with a NOODP tag (or without DMOZ listing) Google often rewites titles, especially if they are very short/long or spammy (keywords enumerations).

They also tend to append the "brand" if it's not contained in the title, in your case that seems to be KA. Happens more often if your title is relatively short.

You can't force Google to use your title, no plugin or tool will help, but if you make the titles a little longer there is a good chance Google stops adding KA at the end.

You can't really do much with what google shows in serp. My guess is that you included that word in your anchor text and now google is showing that in title. Sometimes when I register an expired domain and change the homepage title to something else, google stars showing the title of old site (as the title of old site is also present in anchor text).

starki said:

In contrast to common believe, title tags aren't something Google always uses 1:1 for the SERPs. For example, without a NOODP tag Google may decide to use the DMOZ description if it seems to fit better in Google's opinion. Even with a NOODP tag (or without DMOZ listing) Google often rewites titles, especially if they are very short/long or spammy (keywords enumerations).

They also tend to append the "brand" if it's not contained in the title, in your case that seems to be KA. Happens more often if your title is relatively short.

You can't force Google to use your title, no plugin or tool will help, but if you make the titles a little longer there is a good chance Google stops adding KA at the end.

Click to expand...

Thanks a very appreciated. However, my site was not used a Wordpress template, so can not be added any plugins.
In your comment, you mentioned the length of the title tags, yes I've noticed this problem and changed most of them to be 49 or 50 characters, but google still added the keyword which I've ranked with SEO sercie at the end, please see the following picture: