Hook

Allow HTML in Excerpts

add_filter('get_the_excerpt', 'allow_html_in_excerpt');

function allow_html_in_excerpt($text) { // Fakes an excerpt if needed
	global $post;
	if ( '' == $text ) {
		$text = get_the_content('');
		$text = apply_filters('the_content', $text);
		$text = str_replace(']]>', ']]>', $text);
		/*just add all the tags you want to appear in the excerpt --
		be sure there are no white spaces in the string of allowed tags */
		$text = strip_tags($text,'<b><a><em><strong><h1><h2><h3><h4><h5><h6><ol><li>');
		/* you can also change the length of the excerpt here, if you want */
		$excerpt_length = 55;
		$words = explode(' ', $text, $excerpt_length + 1);
		if (count($words)> $excerpt_length) {
			array_pop($words);
			array_push($words, '[...]');
			$text = implode(' ', $words);
		}
	}
return $text;
}