The investigations show that cross-cumulation of origin is a new tool of easing stringent rules of origin of goods (ROG) in the regional trade deals (RTD) in the economy of global chains and growing protectionism, which is not characteristic of the Eurasian Economic Union (EAEU). The article gives consideration to a legal and institutional commitment of EAEU to using innovation in the sphere of preferential ROG. The existence of multiplicity of wordings of cumulation concept, its types as well as verification systems in different RTD determines the use of comparative analysis of preferential ROG in EU (European Union), ASEAN (Association of South East Asian Nations) and EAEU as the main investigation method. The following findings have been made on the basis of analysis of regulatory and legal framework of preferential rules of EAEU and practice of application thereof: legislation of the Union is developing, though, it is incomplete — a key document on preferential rules is absent, which creates a legal uncertainty in the sphere of ROG; organization of free-trade zones (FTZ) of EAEU with the third countries is progressing slowly not meeting the requirements of development of Big Eurasia; application of diagonal and full cumulation is admissible in EAEU agreements on FTZ, but due to a requirement of direct supply and a complicated system of certification and verification of origin, customs offices frequently refuse to grant preferential tariffs to foreign trade operators. Signing of new EAEU agreements on FTZ, activation of all forms of cumulation in the existing and new FTZ will contribute to expanding the ‘zone of origin’ in the territory of the Eurasian space with the center in EAEU. Full change-over to electronic certification and verification of origin will help reduce business expenses, hence, make EAEU countries more attractive for integration into transcontinental supply chains.