最合适的答案是background-position的新四值语法，但在所有浏览器都支持它之前，最好的方法是按照以下顺序组合之前的响应:

background: url(image.png) no-repeat 97% center; /* default, Android, Sf < 6 */
background-position: -webkit-calc(100% - 10px) center; /* Sf 6 */
background-position: right 10px center; /* Cr 25+, FF 13+, IE 9+, Op 10.5+ */

据我所知，CSS规范并没有提供您所要求的内容，当然，除了CSS表达式之外。除去你不想使用表达式或Javascript的假设，我看到了三个hack的解决方案:

Make sure your background image matches the size of the container (at least in width) and set background-repeat: repeat or repeat-x if only the width is equalized. Then, having something appear x pixels from the right is as simple as background-position: -5px 0px. Using percentages for background-position exhibits special behaviour that is better seen than described here. Give it a shot. Essentially, background-position: 90% 50% will make the right edge of the background image line up 10% away from the right edge of the container. Create a div containing the image. Explicitly set the position of the containing element position: relative if not already set. Set the image container to position: absolute; right: 10px; top: 10px;, obviously adjusting the final two as you see fit. Place the image div container into the containing element.

试试这个:

#myelement {
  background-position: 100% 50%;
  margin-right: 5px;
}

注意上面的代码会将整个元素(不仅仅是背景图像)向右移动5px。这对你的案子来说可能没问题。

这个问题已经被问到很久了，但我刚刚遇到了这个问题，我是这样做的:

background-position:95% 50%;

另一个我没有看到提到的解决方案是使用伪元素，我相信这个解决方案将适用于任何CSS 2.1兼容的浏览器(≥IE8，≥Safari 2，…)，它也应该是响应:

element::after
{
content:' ';
position:relative;
display:block;
width:100%;
height:100%;
bottom:0;
right:-5px; /* 10 px from the right of element inner-margin (padding) see example */
background:url() right center no-repeat;
}

Example: The element eg. a square sized 100px (without considering borders) has a 10px padding and a background image should be shown inside the right padding. This means the pseudo-element is a 80px sized square. We want to stick it to the right border of the element with right:-10px;. If we'd like to have the background-image 5px away from the right border we need to stick the pseudo-element 5px away from the right border of the element with right:-5px;... Test it for your self here : http://jsfiddle.net/yHucT/

有一种方法，但不是每个浏览器都支持(见这里的覆盖)

element {
  background-position : calc(100% - 10px) 0;
}

它适用于所有现代浏览器，但IE9可能会崩溃。也没有覆盖=< IE8。