You can try...
//css
.gritter-center{ position:fixed; left:33%; right:33%; top:33% }
//Javascript
$.gritter.add({ title: ‘This is a centered notification‘, text: ‘Just add a "gritter-center" class_name to your $.gritter.add or globally to $.gritter.options.class_name‘, class_name: ‘gritter-info gritter-center‘ });
ref: https://stackoverflow.com/questions/18461530/jquery-gritter-set-position
原文：http://www.cnblogs.com/pinganzi/p/7048649.html