Write quality content
This is the first step. Good writing may not automatically attract readers but bad writing will surely repel them. Make it interesting, unique and original. Read good articles related to content creation(Eg:Copyblogger.com).
Comment on other blogs. This is the surest way to attract blog comments. Find other blogs that are interesting, especially if they are in the same niche, and comment on them. Add value to their conversation. Don’t just add “Great post. Come back to my place.” like comments. Write somthing about your openion, suggestion, your views or if you know more explain it.
Ask for reader input
To attract more comments is to simply ask for them. At the end of a post, ask for your readers’ feedback. Let them know their input is appreciated.T his doesn’t have to be some big long plea for comments, it can be something as simple as “What do you think?” or “If I missed anything, let me know!”.Make asking an interesting question your goal rather than just saying something like, “comments any?”.At then end of most posts they have some sort of call to action prompting their readers to comment and it’s easy to see the results of their efforts.
Respond/Reply to comments
Respond to them publicly in the comment section and Engage them in a dialog. If you want to attract more comments on your blog, you absolutely MUST let people know that you’re hearing them. If someone leaves a comment on your blog, respond to it! Thank them for it, answer their question, or just simply continue the discussion. The Comment Relish plugin helps with this by automatically generating a response to a new commentator.
Make commenting easy
Make it easy for people to comment on your blog because The more hoops you make people jump through, the fewer comments you’ll get. Captcha’s work, but they put the burden of spam protection on the commenter and not on the blog author. Instead, consider using a good spam filter like Akismet or Defensio.
Consistency is the key. When your readers know what to expect from you they will be more likely to engage in conversation and participate more actively.
Reward quality commenters
If you want to reward quality commenters then consider turning off the NoFollow attribute in your comments. The short version is that Google introduced NoFollow to discourage comment spammers. To turn of NoFollow in WordPress get the DoFollow plugin. The easiest and most obvious is to use Top Commentators plugin (I used in my blog) or you can highlight a comment in your post.
Be Open Ended
If you say everything there is to say on a topic you’re less likely to get others adding their opinions because you’ll have covered what they might have added. So leave something to talk about….
I noticed a good article on problogger about 10 Techniques to Get More Comments on Your Blog .