Existence of a group of principles which have been set a result of a long historical development about real rights field is assumed. The principles that dominate the field of a real rights is also valid for mortgage right, which is a type of a real rights; and mortgage of properties, which is a type of mortgage right. Along with principles set for real rights developed regarding the mortgage of properties, major fields of Law of Property, some other principles are also developed and the mortgage of property is implemented in accordance with these principles. The principles which dominate the mortgage of property are; principles of certainty, principle of public domain, principle of stability of mortgage degrees and principle of warrant. The principle of certainty in mortgage of property answers two major questions of on what type of properties a mortgage could be established and the characteristics; and what type and what amount of receivable will be put under warrant by a mortgage of property. Within this context, questions such as whether a certain part of property would constitute mortgage or not, and under what conditions foreign currency debts could be warranted with foreign currency type should be answered