This theoretical and practical part is related to the analysis and studies of the contractual obligations under the private international law. This work is divided into three parts, where respectively, the first part deals with the general part of the contractual obligations; the second part deals with the specific contracts, which are actually found also in a general regulation under law No. 10428, dated 02.06.2011 “Private International Law”; and the third part deals with the international and national jurisprudence aspect. This work as based on the ex-positio sinkronik system aims at giving a minimum contribution in the application of the international private law and clarifies the omission, collision and legal problematic aspects in practice. At the end of this work, there are our conclusions which serve as a deduction over the analysis and studies done to this part of the private international law.