The present invention relates to a modularized patient-specific registration guide and a system using the same and, more specifically, to a modularized patient-specific registration guide capable of rapidly carrying out an initial registration step for a bone, which is a surgical site, and inducing a registration step to be easily performed even during an operation, and a system using the same. The modularized patient-specific registration guide, according to one embodiment of the present invention, is a registration guide manufactured according to a three-dimensional shape of a bone obtained in an imaging device, the registration guide comprising: a first member having one or more markers and one or more extending parts that come in contact with the bone, and having a groove on one side thereof and a second member accommodated in or separable from the groove of the first member and having one or more markers.
