Processes for manufacturing a composition of a solvolysis product of an ethylene-vinyl ester copolymer, which comprises: conducting solvolysis of an ethylene-vinyl ester copolymer (A′) and a modified ethylene-vinyl ester copolymer (B′) comprising a unit derived from a compound represented by the general formula (2) in one system to manufacture the composition of a solvolysis product of an ethylene-vinyl ester copolymer comprising a solvolysis product (A) of the ethylene-vinyl ester copolymer and a solvolysis product (B) of the modified ethylene-vinyl ester copolymer comprising a unit represented by the general formula (1), wherein a ratio of an ethylene content (B′)/(A′) of copolymer (A′) and copolymer (B′) in conducting solvolysis is 1 or more, and a blending ratio (B′)/(A′) of the ethylene-vinyl ester copolymer (A′) and the modified ethylene-vinyl ester copolymer (B′) is from 50/50 to 1/99 by weight: