The growth of web 2.0 provides a great medium for people to share opinions, comments and emotions. Web Opinion Mining or Sentiment analysis is one of the tasks in text mining that aims to develop system to automatically extract, identify and classify user’s opinion from text written in natural language, user generated content or user generated media. Organizations are interested to get feedback on their products and customer service for business intelligence. Individuals are also interested in other’s opinion for decision making. This survey presents the details of recent works available in the literature for the field of Sentiment Analysis. The existing techniques are grouped into categories based on the methods. The aim of this survey is to provide a summary of current research activities on this area and implementation of various useful techniques applied on sentiment analysis.