First of all lets define for those of you the term: Trackback. Trackback is a way to notify a website when you publish an entry that references it.
When you send it a trackback, a link with a short excerpt of your entry will appear on the referenced website.

Separating your trackbacks and comments requires a minimum coding work to do. First of all please make a backup of your comments.php file just in case something goes wrong.

Here we go:

1 ) Access your comments.php file and locate the following code:
<?php foreach ($comments as $comment) : ?>

Immediately after the above code, you’ll want to place this code:
<?php $comment_type = get_comment_type(); ?>
<?php if($comment_type == 'comment') { ?>

2 ) If you scroll down a little bit you will locate the following code:

<?php endforeach; /* end for each comment */ ?>

This will filter out all of the trackbacks and pingbacks from your main comments loop. Now we need to create a second comments loop to display the trackbacks and pingbacks.

3 ) Almost immediately below the code from step 2 you should find this code:

<?php else : // this is displayed if there are no comments so far ?>

Immediately before the above code, you’ll want to place this code:

<h3>Trackbacks</h3>
<ol>
<?php foreach ($comments as $comment) : ?>
<?php $comment_type = get_comment_type(); ?>
<?php if($comment_type != 'comment') { ?>
<li><?php comment_author_link() ?></li>
<?php } ?>
<?php endforeach; ?>
</ol>