How to add sitemap.xml in Webmaster Tool ?

First you need to generate sitemap.xml. Then upload it in site through FTP. (First upload it in site after that webmaster tool can call it automatically.) After that go to webmaster tool in site configuration option. Then open sitemap. Click on the add sitemap in right side on webmaster tool. put /sitemap.xml in bar. Click on check option. If it shows successfully added then click on submit option. Hence you can add sitemap.xml in webmaster tool.