The Page Rank Of A Website depends solely on your inbound links.The PageRank of a website is calculated with the help of the following equation:
PR(A)=(1-d)+(PR OF LINK PAGE 1*D/NO OF LINKS IN PAGE1)+ (PR OF LINK PAGE 2*D/NO OF LINKS IN PAGE2)+.....+(PR OF LINK PAGE P*D/NO OF LINKS IN PAGE P).
Where A,is your website
D is a damping factor =0.85
link page 1,2...,P are the pages that has a link pointing to your website and can be found out by conducting a search on Google with link:
www.website.com