The design is okay.. for your site's title (in the header area) I would center it because it's too close to the edge..
Maybe you can use javascript on the search box to display/hide the word "search...", it doesn't look like a search box
Add an about and contact page and make your header logo smaller in side vertical wise. Then add a description and keywords to your header.
Very thanks for advices, i updated my blog design i made new header changed some colors and background
the header does not blend with your background and too much space on your left and right margin.. its too crowded on the body part of your blog..looks untidy..