Do you mean Page Rank? if yes, then you have to build high page rank links with high domain authority websites. After doing that you can easily increase your web page rank.
But dear, i have heard about domain authority and not page authority. Now, I may be wrong here. Can any one please correct me if I've got it wrong.
Page Authority/Domain Authority which is given by MOZ can be easily manipulated with the amount of incoming links to your site. They don't even consider whether the incoming links are quality ones. So don't worry about it. Keep building more number of incoming links to your site.
Page Authority and Domain Authority play a very important role in ranking of a site. I would however suggest that you pay attention to the link quality as well simply because Google Penguin is really strict when it comes to domain's backlink profile and you wouldn't want your site to go down.
Improve the content of the website, Have some informative content and should be unique... It will increase the authority, Will increase organic links and also it will help you in SERP.
Thanks for giving your valuable answers, now I have understood the difference between Page authority and domain authority. Before going through these answers, I was under the impression that moz gives only domain authority and not page authority. Thanks again for clearing my doubts.
Page Authority and Domain Authority play no role whatsoever in your ranking... Sorry, dude but google don't use that rubbish to rank websites and as said before moz stats can easily be manipulated. It's even less relevant than pagerank. Quality content, well designed website and a few really good links will rank you regardless of moz stats.
Domain authority is the authority of the domain as a whole. Page authority is given by Moz to each separate page on the domain. Both are important, and both are heavily influenced by backlinks.
Ashutosh, Page authority refers to How important a page is? And this is calculated by the number of links which are pointing to a page. And every page have different page authority of their own according to the relevance. The only way to increase it is building quality backlinks for each page. Which if counted all over increases the domain authority of your website. Hope I explained it as per your needs.
Then you should read a lot... Domain authority is the authority of the WHOLE domain while every single page has unique PAGE Authority... It's hard to do this... But I could tell you that Google loves to see that you get backlinks from websites with High Authority...