animation-play-state：

css:

.play-state{
-webkit-animation:f1 2s 0.5s infinite linear forwards alternate;
-moz-animation:f1 2s 0.5s infinite linear forwards alternate;
position:relative;
left:10px;
width:100px;
height:100px;
margin:10px 0;
overflow:hidden;
}
.play-state:hover{
-webkit-animation-play-state:paused;
-moz-animation-play-state:paused;
}
@-webkit-keyframes f1{
0%{left:10px;}
100%{left:500px;}
}
@-moz-keyframes f1{
0%{left:10px;}
100%{left:500px;}
}

html:

<div class="play-state">鼠标移过来我就停，移走就运动，好听话哦！</div>