Hello Alia and welcome back!
It's an odd topic - where did you get it from? It's not very well-written for an IELTS topic, so that makes our job of writing a reply very difficult. If it was just "How have mobile phones affected our lives?" it would be a lot easier!
Vocab and Usage
- 'Way' - can be omitted (left out).
It has changed our communication way - it has changed how we communicate.
- 'Research' is a non-count verb: it can't be plural.
Researches prove that mobile phones have serious side effects - Research has proved that mobile phones have serious side effects
“On the other hand” means opposite, in contrast. It does NOT mean “here’s another example” or “in addition,” or “another point is that.”
On the other hand, some scientific researches prove that mobile phones have serious side effects on our central nervous system particularly on the brain.
You need to change "On the other hand" to “In addition” or “Another point is that...”
To sum up, although mobiles have so many practical uses which are useful and advantageous, but still we should treat it more cautiously to minimize its undesirable side effects as much as we can
Don’t use “although” in the same sentence as “but,” or “but” in the same sentence as “although.”
First of all, it is a fact that mobile phone has transformed our way of communication or our way to do business. Now, every one have a mobile or more, even the children of 10 years, in order to connect them with their parents, when they go out to school or to buy some thing.
You have a clear topic sentence which tells the reader you are going to talk about (1) communication and (2) business. However, the second sentence above does not say how communication has changed – it just says kids have phones, or (possibly ) that everyone talks to their parents. You need to develop your idea fully.
Also, all businessmen depend on it in a large scale during their work as it facilitates their communications all over the world.
Businessmen have had landlines for over a century. How have mobiles changed their work? You need to give an example. Again, the idea is not developed fully. Have a look at Band 5 in the IELTS Writing Task 2 Descriptors “presents some main ideas but these are limited and not sufficiently developed:” (http://www.ielts.org/pdf/UOBDs_WritingT2.pdf) You want more than Band 5!
Run-On sentences and Comma Splices
Starting with its social drawbacks, it consumes so many hours from the user's time playing games, chatting and other activities.
This is a fragment AND a comma splice. Writing is not the same as speaking. This sentence would be fine in speaking, but it should be written as two or more sentences (and with some pronoun reference changes):
The mobile phone has several serious effects on society. First of all, it's an incredible time-waster. Many users spend hundreds of unproductive hours playing games, downloading annoying ringtones, changing their screen settings, and sending idiotic texts.
The sentence below:
Finally that leads digital natives to be unsociable lose connections with other people even with their immediate family members.
...needs to be broken up and punctuated. It shouldn't use the word "Finally," since it is only the second idea. Perhaps it could be rewritten like this:
A second point is that mobile phones damage relationships with families and close friends. Mobile phone users become unsociable. They prefer to chat online to acquaintances rather than interact with immediate family members or people around them.