Edit in JSFiddle

body{
    background-color:#CCC;
}
.aerakman-box {
    -webkit-transition: box-shadow 1s;
    -moz-transition: box-shadow 1s;
    -o-transition: box-shadow 1s;
    transition: box-shadow 1s;
    background-color:#666;
    width:70px;
    height:70px;
    position:absolute;
    top:50px;
    left:200px;
}
.aerakman-box:hover {
    -webkit-transition: box-shadow 1s;
    -moz-transition: box-shadow 1s;
    -o-transition: box-shadow 1s;
    transition: box-shadow 1s;
    /*Gölge*/
    -moz-box-shadow: 0px 0px 20px #333399;
    -webkit-box-shadow: 0px 0px 20px #333399;
    box-shadow: 0px 0px 20px #333399;
}

<div class="aerakman-box"></div>