ABSTRACT From the last 30 years QSAR study become important to help in designing of drugs. Many software and hardware are used in discovery of drugs. QSAR techniques employ powerful computers to generate large data bases result. Quantities structure activity relationship and quantative structure property relationship is essentially computerised statistical methods which help to explain the observed variance in the biological effect of certain classes of compound. It assumes that a biological activity of certain compound is a function of various physico chemical properties are favourable to the concern activity. QSAR involve themathematical and statistical analysis of SAR data which help to minimize the molecular modification. The ultimate objective of the present study is to understand the force governing the activity of a particular compound. QSAR is thus a scientific achievement and an economic necessity to reduce empiricism in drug designing. The purpose of this study is to describe the techniques like ANN, multiple linearanalysis, partial least square method. The study further extent the types of QSAR like 1D , 2D, 3D,4D,5D etc used in designing of molecule with the help of different software. QSAR is thus a scientific achievement and an economic necessity to reduce an empiricism in drug design to ensure that every drug synthesized and pharmacologically tested should be as meaningful as possible. The uses of different parameter are important to calculate biological activity of molecule. Key words: QSAR, Drug design, QSAR PARAMETER, MLR, ANN, Free energy model, Quantum mechanical method.