This question already has an answer here:
I'm wondering which of the following two orders is semantically correct in HTML:
1. <h1><a>Header</a></h1>
2. <a><h1>Header</h1></a>
<h1><a>Header</a></h1>
<h1> is a block-level element and <a> is not, it is syntactically invalid HTML to have block level elements inside inline elements (at least until HTML5) which is how the other way would be.
This answer on a duplicate question is better than mine: https://stackoverflow.com/a/7023551/20578
But, for posterity:
Semantically, there’s no difference. Remember, “semantic” just means “related to meaning”, and meaning is just something agreed between humans (because computers don’t natively do meaning, that’s a human brain thing). No-one’s got time to agree that one of these virtually identical options means something different to the other :)
Surprisingly, they’re actually both valid as well, as of the current HTML spec, because <a>’s content model is defined as “transparent”, i.e. the same as its parent.
See:
And:
(That assumes that <a>’s parent can have an <h1> as its child)
However, it’s not valid under previous versions of HTML:
From a semantic perspective: both (or neither).
(From a structural perspective, OTOH, before HTML 5 an anchor cannot contain a heading, and since browsers aren't all HTML 5 capable yet you should avoid the new form of the construct where possible)
If you are creating a link target, then <h1 id="target_name"> is preferred to <h1><a name="target_name"> anyway.
If you are creating a hyperlink, then having the most important heading on the page link somewhere else is somewhat dubious from a semantic point of view.
I'd say <h1><a>, because <h*> are block elements and <a> is inline element, so it seems more natural to keep the inline element inside a div block, not the other way round.
The header should be first in my opinion but I doubt that search engines would really mind what way round they are, inside the H1 just seems cleaner to me...
Since h1 does not directly correspond to a viewable object they both are correct.
来源：https://stackoverflow.com/questions/5341451/what-should-come-first-in-html-an-anchor-or-a-header