You probably make links to your another posts. If you want to disable it, install a plugin called No Self Pings.
Pingback is generally a confirmation when somebody links to your posts from his/her own blog. There is nothing good or bad about it as it is just a facility to get notified of the backlinks! Read more about it here... PINGBACKS Regards, RightMan
i am getting it from topsy.com which have good PR 6. But i am getting pingback after every new post...
Why is it a problem? You can moderate ping backs so they are not auto approved. Or disable them entirely. Or find the site linking to your content and ask them to stop.