i want to know that without page rank bookmarking sites is effective for keywords ranking, please share some tips.

Page Rank is a link analysis algorithm developed by Google, Inc. It is used to measure the amount of links a page has to determine it's relative importance. The higher the Page Rank a URL has, the higher it's authority is with Google.Page Rank is one of the few factors that webmasters can use to determine the strength of a web page.

It will be a waste of time. You need to submit your site to good high page rank sites to improve your keyword position.

page Rank is important for our site.Google giving the Page Rank to website.for increase page rank u need to do directory submission. One of the main benefits of directory submission is highly quality back links.