Can we improve bounce rate of blog?

If you have a lengthy post, you can divide the post into pages. You can google out for the method depending on whether you're using wordpress or blogspot. I've been using a very old wordpress plugin that does the job. It stays well under 10%. 

This is interesting, TS... I have been writing a lot of articles of 1400 words or more and have always crammed them into a single post. Do you think I will benefit if I break them into two of 700 words each and make Google feel a reader has stayed on for more than one post?

If your content can be divided into categories/ subjects /sub topic within that post, yeah! It depends a lot on the content. Like multiple chapters for a book. Of course, too much of sub-division of a post is equally annoying. I divide a review post into pages, which can be categorised as 'introduction and specifications', 'Internal/external impressions', 'installation impressions', 'testing methodology and benchmark' 'each benchmark posts', 'conclusion' and 'purchase links'. In 2011 the bounce rate of mine was about 85%. It also helps people to check the part that they want to check rather than going through everything. 

Personally, I find dividing content into different pages a trick. Mostly listicles would do that I suppose. Unless there are images, that should be separated, or make sense only when viewed individually one at a time, I don't think blogging should go into pages

Bounce rate is the time the user spends on the landing page, irrespective of the page he/she enters your blog from, before the unload event occurs as a result of the user exiting your blog's page.

This affects the blog's ratings negatively because a higher bounce rate translates into a lower content quality, (quantitatively), and hence low ratings.

One of the many ways includes making your blog posts appealing, using media wherever required/possible. Make the look and feel consistent throughout all the pages on your blog, which essentially means that your blog posts should have similar formatting throughout. Plus, I beg to differ, from the point above regarding premium blog themes. Getting yourself a premium theme is not one of the requisites for making your site appealing.

Always ensure that the blog post is just long enough ensure that the casual reader doesn't have to spend too much time reading through the content, all of it. This will help you reduce the bounce rate. If you can afford (which means, if your blog niche/ post topic allows), do make use of colours.

As almost everyone has suggested above, if possible, break down your blog posts into different pages. Though, this will make a single blogpost span over multiple pages, it will still help keep the page length in a controlled state. However, this should be done only if you think you can the user can still relate to what was there in the previous page.

The thumb rule for making blogposts is to keep oneself in a casual reader's shoe, and then think of what could be done with the blog post to make the reader read it. You'll get most of your answers.

Thanks to all of you for a wonderful suggestions.