<!DOCTYPE html> <html> <head> <style> .anim{ width: 100px; height: 100px; background-color: red; } .anim-show { transition: 0.7s; transform:translate(100px,100px) scale(1.5); } .anim-show1 { transition: 0.7s; transform:translate(100px,100px) scale(1); } </style> </head> <body> <div id="a" class="anim anim-show1"></div> <script src="http://www.jq22.com/jquery/2.1.1/jquery.min.js"></script> <script> var i = 0; var int=self.setInterval("clock()",700); function clock(){ i++; if(parseInt(i/2) == i/2){ $("#a").addClass("anim-show"); $("#a").removeClass("anim-show1"); }else{ $("#a").removeClass("anim-show"); $("#a").addClass("anim-show1"); } } </script> </body> </html>