The influences of glucono-δ-lactone (GDL) on the structural characteristics of red seabream (Pagrosomus major) surimi gel were studied in terms of protein components, secondary structure and aggregation of protein under pasteurisation conditions. The results showed that most of the salt-soluble protein form a gel, and a small amount of water-soluble protein plays a role in the addition of GDL under low-temperature heating conditions during surimi gel formation. The active sulfhydryl content of actomyosin increased but the total sulfhydryl content decreased as the content of GDL increased. The percentage of β-folds increase and that of α-helices decreased as the content of the GDL increased. SDS-PAGE results suggest that adding GDL can induce more MHC cross-linking and that the degree of cross-linking is higher than that in the high-temperature treatment samples.