i have a wordpress blog installed on my webhost. i am planning to change my blog title but im afraid to negatively affect my SEO for it.

will changing the title reduce my number of hits?

JUST THE TITLE of the entire blog. not the address.

Changing the title of your blog will impact your SEO, for the better or the worse. So, make sure it is for the better 🙂
The title of your blog should contain your keywords. As long as you stick to that rule, or go towards that rule, you will not lose anything.