I am in plan to Change my Wordpress blog templates to some other will it have any adverse effect in SEO of my blog ?
I am planning to change whole the template only content and title would remain the same. Will I loose content if I change my wordpress theme ?
If any of the existing internal links get severed which can happen when you change your link template, then yes there is a decent chance your organic search engine traffic will be adversely be affected. There are only good reasons I can think of to change template after the site has been up and running for a while. The first is that you think that the on-page optimization you started with is really sub-optimal and you are ok taking a hit, let's say for the next 6 months, because you think starting over from scratch will offer you greater opportunities down the road. The second reason is that you are relatively happy with your on-page optimization but you just want to change the design and look of your site. A lot of prominent bloggers have done this and the key is to have someone who is experinced with SEO work with the designer to make sure not of the existing internal link structure is altered. Think of it not as a template change but a skin change where the skeleton remains intact.
Depending on the type of site that you are hosting, I'd suggest that you get an opinion from people who visit your site based on their assessment you can easily judge just how much traffic you do or do not stand to lose, a Poll would for example be nice =]
I dont think do it will effect your SEO But My suggest Before do all this to your live site . First make a new directory and test all things there and then replace or update it. This way you can test it properlyt hat ever thing is working fine.
I think if your content is same and everything remain same then it won't do any bad to your rankings..
I'd still suggest setting up some form of a poll or something, that'll help alot in making your visitors feel more involved when it comes to updating your site =]
it will give little affect as some theme have h2 tags for sidebars and others use h3 tags...even for post title have the same issue