Post and related link

Hi

I have this code in a post.php (Single Post template):

<?php if (have_posts()) : ?>
<?php query_posts('posts_per_page=1'); while (have_posts()) : the_post(); ?>

Every time I create a post and put the link to
web browser It show always the last post not the
one is related to the link name.

Any idea why is that ??