Nowadays, there are no country that have no idea about bankruptcy. In Bankrupcty, we understand that there is a connection between the debtor and creditor. Bankrupcty happens as a result of Creditor who can’t fulfill his responsibility to pay back the debt. In bankruptcy, we are familiar with 3 kinds of kreditor which are separatist creditor, preferent creditor and concurent creditor. Separatis creditor is creditor that have ability to demand his or her right directly if the bankruptcy occurs. This thesis will discuss the legal protection of separatist creditor in exercising the mortgage and the legal protection of this creditors in the case of PT. DwimasAndalan Bali vs. PT. KarsaIndustamaMandiri. The method use for this research is qualitative analysis as well as statue approach and case approach. The protections provided for the separatist creditor are covered in Law No. 37 Year 2004 clause 55, 56 and 59. In PT. DwimasAndalan Bali vs. PT. KarsaIndustamaMandiri case, the protection is not compatible with Law No. 37 Year 2004. In clause 55 it is stated that separatist creditor can execute his right make it like the bankruptcy never happened but because there is rejection of the unit owner, the auction can be canceled and for this reason, the legal protection for the separatist creditor has not considered compatible with the Law No. 37 Year 2004.