Today astronomical observations confirm that both radio Pulsars and Magnetars tend to bernfound in the same locations of the Milky Way, in regions where stars have recently exploded asrnsupernovae.rnThe question has been: if they are located in similar places and are born in similar ways, thenrnwhy does a magnetar’s magnetic field decay in just 104 years, when a normal pulsar decays inrn106 -107 years and why are magnetars (1014 -1015 Gauss) formed with stronger magnetic fieldsrnthan radio pulsars (1012 Gauss ).rnIn these work I will try to suggest possible answers for questions given above byrninvestigating the cause of the variation of the magnetic field and decaying time among neutronrnstars. Moreover, I am also deriving an equation and stating an idea that describes the relationrnbetween magnetic field and decaying time