 <blockquote> <p>The problem is that facebook like will extract meta info but I don't know how to assign the meta with ajax.</p> <p>I tried use append to head int FB.init but it seems not work.</p> </blockquote> <p><strong>Of course</strong> this does not work, because Facebook’s scraper requests your URLs from your <em>server</em> – and does not care about what the DOM might currently look like in any user’s <em>browser</em>.</p> <p>You <strong>can not</strong> add Open Graph meta data client-side.</p>