­The conflict of law rules applicable to the insurance of mass risks have crucial importance for the insurance contracts with international element from the legal and economical point of view, because the legal regime has overwhelming effect on the successful contract implementation. The differentiation between large and mass risks was developed historically in the European private international law by the legal regulation contained in the life- and non-life insurance directives, which contained conflict of laws rules designed for insurance c­ontracts, which had to be implemented to the legal orders in the EU Member States. The relevance of the distinction between large and mass risks for the determination of applicable law is given also after entry into force of the Rome I Regulation, which had to codify in its art. 7 conflicts of laws rules of the insurance contracts for the purpose of elimination of the shortcomings, which were typical for the previous legal regulation, which was implemented from the EU life- and non-life directives also to the Czech legal order.