Murraya koenigii (L.) Spreng is a tropical to subtropical tree in the family Rutaceae. Its leaves are used as condiment in traditional cooking. The plant is also a host plant for swallowtail butterflies like Papilio polytes and Papilio demoleus. In this study we have observed and documented complete life cycle of Common Line Blue butterfly Prosotos nora (C. Felder,1860) on this plant inflorescence and recorded six complete life cycles from egg laying to eclosing over a period of four years.