Identification of opinion leader is very important in this world of internet because with the identified opinion leaders in any application area such as Knowledge related sites, followers or other individuals can get valuable information more efficiently through direct communication with opinion leader. Internet i.e. WWW (World Wide Web) is the huge and very popular way of information broadcasting and communication. This huge www has so many web structures and within one structure there would be millions of web resources (contents, links) may exist. There are large numbers of webpages on the web which are linked to each other through hyperlinks. So, graph based techniques can be used to identify opinion leader i.e. techniques for ranking the results to provide the "best" results first. Different algorithms are there which are used for link analysis i.e. for ranking the web pages like PageRank (PR), Weighted PageRank (WPR), Hyperlink-Induced Topic Search (HITS), Spamming Resistant Expertise Analysis and Ranking (SPEAR) etc. This paper is focused on the study of different ranking techniques. Further this paper shows advantages, limitations and comparison of these techniques.