Try this ..
<!DOCTYPE html>
<html>
<head>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js">
</script>
<script>
$(document).ready(function () {
$("#btn").click(function () {
var allListElements = $(".jcrop-holder").find('*');
debugger
for (var i = 0; i < allListElements.length; i++) {
if (allListElements[i] != 'img')
$(allListElements[i]).remove();
}
});
});
</script>
</head>
<body>
<button type="button" id="btn">Click Me!</button>
<p>
<div class="jcrop-holder">
<div>1</div>
<div>2</div>
<div class="img">img</div>
<img class="img" />
</div>
<div class="jcrop-holder">
<div>3</div>
<div>4</div>
</div>
</p>
</body>
</html>