A sitemap could contain only 10,000 links. So you need to create a 2nd sitemap for the excess links. And then use a sitemap index file which you could submit to search engines. Check this link. http://www.sitemaps.org/protocol.php#index
Sorry I was wrong. A sitemap can contain a maximum of 50,000 links (file size not more than 10 MB). [got confused with the numbers by seeing your post]
ty but there is another thing i wanna learn. How can i creat another sitemap from the link which left last ?