Why Google giving less value to my PR3 website?

I have a website which has a google pageRank 3. I always try to create great posts…
but google do not rank it on it’s first search results like other pr3 site…

There’s a lot more to SEO than PR (which is all but irrelevant, these days, it seems). Have a read up on our SEO FAQ to get a sense of what’s involved in improving rankings: All You Need To Know About SEO