Problems in meta tag update
 

Presently i have changed the meta tag of my website.After that i have checked my website on Google Search engine,but it has been showing my previous meta tag in search result.Why it does not show my new meta tag on search result?

It will take some time. Do one thing, submit your website on social bookmarking sites. This will help to index new meta.

after every changes to your website, please submit your site in the crawler in the google webmaster.

There is some basic solution for meta tag update
1 Put Real and quality Content in Your Meta Description Tag
2 Don't import too many Lists of Keywords into Your Meta Description Tag.

It take some time because indexer take time to crawl your website

Putting meta description tags can sometimes cause problems for your website. Everything ... I will discuss here the potential problems this tag can cause your site and how you can avoid them. ... This page was last updated on 25 June 2014.

It can take at least a week so just be patient and it will change.

you change the meta, wait a while google will index

I'm having a probelem that is partially solved by a post I read at
macromedia.com
Unable to Assign Keywords in Pages Created from a Template
Product: Dreamweaver Platform: All Versions: 2.0 and above ID: 13886
Issue
Keywords are not added to a page created from a template by using either
the menu command Insert>Head>Keywords or the Head category,Keyword
button of the Object Palette.

It ake some time to index properly on search engine

do you know how much time it takes?