Disclosed are a fixture for a dental implant and an implant system comprising the same. The implant system of the present invention comprises: a first fixture having a first body part and a first continuous screw part which is formed in a spiral around the outer circumferential surface of the first body part and is formed continuously without a break; and a second fixture having a second body part that is identical to the first body part, and a second continuous screw part which is formed in a spiral around the outer circumferential surface of the second body part and which has an outer diameter that differs from that of the first continuous screw part. The present invention allows implant operations to be carried out in a more straightforward fashion than hitherto since, even if initial fixture placement fails, a subsequent fixture can be placed straight away without any further drilling work.