Embodiments of the present invention relate to an olefin resin composition and a method for manufacturing an encapsulation material for an optoelectronic device, and can provide an encapsulation material having excellent adhesive force with respect to a front substrate and a back sheet included in various optoelectronic devices. Also, the present invention can provide the encapsulation material, which does not have a negative effect on parts, such as optoelectronic elements or wire electrodes encapsulated in the optoelectronic devices, and on a working environment, and which can maintain superior workability and economic feasibility in device manufacturing.