asynchronously load script with html 5 async attribute

I use async attribute with the simplest way :
<script async type="text/javascript" src="path/jquery-1.10.2.min.js"></script>
for all .js in my page but problem is that once it loads good and once no.
Especially when i refresh page .js scripts doesn't load.
As soon as i delete async, everything works fine but it is no solution.
Someone know, where problem could be ?
Thanks