Abstract: We designed a system that track the changes to a particular area of user's interests on the Web and generate a summary of emerging topic back to the user. This system consists of three main components, which are Area View System, Web Spider and Summary Generator. Area View System as a Meta-search engine will direct the user keyword to a commercial search engine, get the hits, do further analysis and derive a number of most relevance domain sites. Then, Web Spider will dispatch and scan all these domains at a certain time interval to collect all the modified and newly added html pages. Lastly, Summary Generator will first extract all the newly added sentences or Changes from the collected html pages and then count the term weight in the Changes by adapting a newly innovated algorithm TF*PDF (Term Frequency * Proportional Document Frequency). Terms that deem to explain the emerging topic will be heavily weighted. Sentences with the highest average weight will be extracted to form a summary of emerging topic. We refer our system as ETTS (Emerging Topic Tracking System).