ABSTRACT:Internet is fast growing and global system, which is most reliable and efficient. Now a day's social networking is increased due to which interaction of people with each other and share emotions, feedback, views, experiences, opinion and feedback about anything. Also the use of shopping sites i.e. online shopping is increasing tremendously and customers used to give their reviews and feedbacks, which are most important for buying or selling any product. But being as a customer it is difficult to read number of reviews every time while shopping. It leads to create confusion. So the technique which plays an important role in opinion mining and summering reviews of customer is data mining. Some existing techniques for opinion mining show only positive and negative comments from the customer reviews which is not efficient. The main aim of this article is to give an overall idea about the work done in past and about the proposed work.