h1 tag should use only once in one page

Proper Use of Header Tags

<h1>, <h2> tags etc. should be used when appropriate. Don't be using <h2> tags as a paragraph or using <div> class="title"</div> to display the title of your page or something.
Here's a few things to keep in mind when using header tags:

• only use one <h1> tag per page
• you can use as many <h2> - <h6> tags as you like in your pages
• search engine crawlers only read basic html

More articles about header tags:

• How To Use Tags – Proper Use Of H1, H2, H3, H4, H5, H6 Elements
• How to optimize keywords in header tags.