opacity: 0.7
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html> <head> <title></title> <style type='text/css'> div { padding: 10px; border: 1px solid black; opacity: 0.7; background: #ccc; } #div1 { position: relative; margin: 50px; } #div2 { position: absolute; top: 20px; left: 20px; } </style> </head> <body> <div id='div1'> div1 <div id='div2'> div2 </div> </div> </body> </html>