Have a look at David's answer here: http://world.episerver.com/forum/developer-forum/-EPiServer-75-CMS/Thread-Container/2015/8/xml-site-map-using-mvc/ He has a few suggestions :)
Theres a lot of tools for sitemaps, take a look at this: https://github.com/Geta/SEO.Sitemaps
Edit: Lars was a little bit faster than me :)
i want to screate a SiteMap in EpiServer CMS as a schedule job.
Any Help appreciated.