In order to improve crystallographic characteristics of CoCr-based thin film as perpendicular magnetic recording media, amorphous Si layers were deposited as an underlayer using a Facing Targets Sputtering apparatus. First, by increasing the film thickness of CoCr, CoCrTa single layer, crystalline orientation and perpendicular coercivity was improved. The CoCrTa thin film showed better crystalline and magnetic characteristics than those of CoCr thin film. As a result of investigating magnetic and crystallographic characteristics of CoCr and CoCrTa magnetic layer on introducing the Si underlayer, it was found that although the 5 nm Si underlayer was very thin, the c-axis preferred orientation of CoCr/Si and CoCrTa/Si doublelayer was improved significantly with amorphous Si thin film.