The import and export features on Blogger give your content a whole new range of portability and freedom, allowing you to save a copy of your blog on your hard drive, or import your blogs into other existing blogs.
Export Your blog
To export your blog, simply click "Export Blog" from the Settings | Other tab.
Then, click the Export Blog button. Your blog will be stored as a Blogger export file (.xml) file which can be kept as a backup on your hard drive or imported into another blog. Exported blogs are not deleted from your dashboard or from Blogger.com.
Import Into an Existing Blog
To import posts and comments into an already existing blog, go to Settings | Other and click on "Import blog" from the "Blog tools" section. Don't worry -- your template won't be affected by imported content. Next, choose a Blogger export file (.xml) from your hard drive and fill out the word verification beneath. By default, all of your imported posts will remain unpublished until you publish them from your dashboard later. However, if you would rather have all posts published immediately, make sure to check the box next to Automatically publish all imported posts before you click Import Blog.
If you didn't choose to have your posts publish automatically, you'll need to manually publish them from the Posts | Imported tab before they will appear on the web. You can either publish all the posts at once by clicking the checkbox at the top and selecting all before clicking Publish, or simply checking the ones you want to publish one by one.Watch a video on how to import and export your blogs