In this paper we optimized geometry of Logain with help of combination DFT/B3LYP method and 6-311G (d, p) basis set. QTAIM calculation shows that out of five interaction O18-H19 having highest interaction energy. The Chemical activity calculated with help of HOMO, LUMO and MESP of loganin. Docking of loganin by swissdock online server shows that PAPNON receptor is more effectively bind with logain as compare to PAPN2.Several biological activity also predicted by PASS software.