i found answer of my question.
find rate-template-thumbs-up-down.tpl.php file in rate -> templates -> rate-template-thumbs-up-down.tpl.php
copy this file and place in your_theme/templates folder.
then override this file by below code:
<?php
/**
* @file
* Rate widget theme
*/
?>
<?php
/*
<div class="rate-label">
<?php print $display_options['title']; ?>
</div>
*/
?>
<div class="like-container">
<div class="likes">
<span>
<img src="<?php print base_path() . drupal_get_path('theme', 'bartik'); ?
>/images/likes.png"></span>
<span><?php print $results['up']; ?></span>
<span> total likes</span>
</div>
<button class="likes-button"><?php
print theme('rate_button', array(
'text' => t('Likes'),
'href' => $links[0]['href'],
'class' => "likes-button-link")
);
?></button>
</div>
<div class="dislike-container">
<div class="dislikes">
<span>
<img src="<?php print base_path() . drupal_get_path('theme', 'bartik'); ?
>/images/dislikes.png">
</span>
<span><?php print $results['down']; ?></span>
<span> total dislikes</span>
</div>
<button><?php
print theme('rate_button', array(
'text' => t('Dislikes'),
'href' => $links[1]['href'],
'class' => "dislikes-button-link")
);
?></button>
</div>