This research study is aboutito examine the behavior of investors about investment decision making into Karachi Stock Exchange (KSE) and its sectors, more precisely it is about to catch the occurrence of herding behavior in KSE. (CSSD) proposed by Christi and Huang (1995) and (CSAD) suggested by Cheng and Khorana (2000) methods are used to estimate the herding behavior in KSE market, by using the daily data of stock prices for period of January 2007 till JulyZOl5. N0 Significant evidence of herding behavior in KSE and but in some of its sectors found in normal market conditions. Further, it is also found that herding behavior changes as the market conditions changes with time to time. Herding behavior is most likely to occur during extreme market“ conditions, in lower tale of market herding have high tendency to occur. It is also found that the bearish and bullish market conditions have movements of herding behavior at lower extreme (bearish) in moSt of the sectors of Karachi Stock Exchange. Supervisor:- Dr. Attiya Yasmin Javid