The various QSAR models have been developed to predict the activities in terms of log 1/C for 29 compounds of 5α- Reductase Inhibitors of humans Type-1 derivatives of 4-Aza-3-oxo-5α-androst-1-ene-17 β-N(X-aryl)-carboxamide with the help of quantum chemical viz., HOMO energy, LUMO energy, absolute hardness, Softness, Chemical Potential and electronegativity and Physiochemical parameter Molar Refractivity ( MR) , Molecular Volume (MV) , Parachor(Pc), Refraction Index(n), Surface Tension(ϒ), Density(D), Polarizability, (α), Average Mass. The comparison between these two type of descriptors models indicates that quantum chemical models are more informative than topological models. The parameter adopted in quantum chemical the calculation is the semiempirical PM3 based. The QSAR model sixth provides a good arrangement between obs log 1/c & predicted activity.