I have found the solution myself. Problem solved.
Example 5
Exclude certain Pages from the list. Suppose you do not want Pages with ID numbers 17 and 38 to be displayed. Modify the call to this template tag in your theme’s sidebar.php. The exclude argument is what removes items from the list.
<ul>
<?php wp_list_pages('exclude=17,38&title_li=<h2>' . __('Pages') . '</h2>' ); ?>
</ul>
