您需要转义i.现在，nth-child正在寻找索引为i而不是0，1，2等的子级.因此，请使用:

You need to escape i. Right now, nth-child is looking for the child that has an index of i, not of 0, 1, 2, etc. So instead, use:

$('#slideshow p:nth-child(' + i + ')').fadeIn('slow').delay(800).fadeOut('slow');

但是，我认为这不会一次完成.实际上，我敢肯定不会.如果没有，请尝试以下操作:

However, I don't think that will do one at a time; in fact, I'm pretty sure it won't. If it doesn't, try something like this:

var delay = 0;
$('#slideshow p').each(
    function (index, item)
    {
        $(this).delay(delay).fadeIn('slow').delay(800).fadeOut('slow');
        delay += 2200;
    }
);

未经测试，但至少应该是不错的伪代码.

That's untested, but should be decent pseudocode at the very least.