Actually I write blog post once in a week & get neutral links from other bloggers. I know google penalized some of the blog networks recently but i am not a part of any network, i get neutral link from other blogs. So my main concern is that what if the blogs which are giving me link back from there site are part of any blog network? So can Google penalized my website for having links on those blogs, If yes, then how to identify blogs which are part of any blog network? I mean i can't stop anyone to giving me link back until the website is not relevant to my content. So what should be the solution?
It is a possibility that you had got penalized maybe because the links from the blog network are not related to your blog.
I dint hear about any penalisation on any blog networks. I doubt google can do that because black hatrs would blast their competition.
If those block which provide you back links are listed for bad quality, there is a strong possibility of being penalized.
You're being far too paranoid and need to relax. You should read this: http://www.seomoz.org/blog/10-myths-that-scare-seos-but-shouldnt-whiteboard-friday
its not very easy to get penalized for having one or 2 links form bad blogs. if it was, then whats stopping your competitor building a few bad links and get your site penalized? if you however have lots of links form blog networks that are penalized by google, then you will be losing all those links which will get your ranking lower.