Here is A list for WordPress Seo Plugins That Will Increase Your websites Ranking .
1- WordPress SEO by Yoast
Widely regarded as the SEO plugin for WordPress. It has an extensive feature set and rave reviews. Give it a whirl, there are alternatives though. Includes XML sitemap features.
2- SEO Ultimate
Another extensive feature set – this one has a 404 error tracker and well as link cloaking for your affiliate links, as well as the standard features. Each module can be disabled as required, so scales with your needs. Quite heavy when fully enabled though.
3- All-In-One SEO
A basic set of features, but still a very popular choice for handling SEO concerns.
4- SEO Friendly Images
Adds ALT and TITLE meta tags to your images so you can start getting valuable Google Images traffic.
5- SEO Smart Links
SEO Smart Links provides automatic SEO benefits for your site in addition to custom keyword lists, nofollow and much more.
SEO Smart Links can automatically link keywords and phrases in your posts and comments with corresponding posts, pages, categories and tags on your blog.
Redirection is a WordPress plugin to manage 301 redirections and keep track of 404 errors without requiring knowledge of Apache .htaccess files.
7- Google XML Sitemaps
This plugin will generate a special XML sitemap which will help search engines to better index your blog.
8- Broken Link Checker
This plugin will check your posts, comments and other content for broken links and missing images, and notify you if any are found.