You can delete your own blog. When you delete your blog, all content in the blog is destroyed.
Warning: Deleting a blog is permanent. Make sure you back up all critical data stored in the blog before deleting it.
To delete a personal blog:
While viewing My Page, click Blogs.
Hold the pointer over the link to the blog and then click the Delete (X) link.
If the Delete (X) link doesn't appear, you don't have administrator access to the blog, and you can't delete it.
When prompted to confirm, click Delete.