Abstract:In order to explore the changes of serum energy indexes of Coilia nasus during spawning migration, 49 serum samples of Coilia nasus were collected from Chongming, Zhenjiang and Anqing sections of the Yangtze River from April 15 to June 5, 2019. The results illustrated that: there was no significant difference in the contents of serum glucose, total cholesterol and low-density lipoprotein during the migration from Chongming to Anqing(P>0.05). No significant differences in the contents of serum total protein, triglyceride, high density lipoprotein and free fatty acid were observed from Zhenjiang to Anqing (P>0.05). The significant differences were mainly concentrated in Chongming to Zhenjiang, in which the contents of total protein and triglyceride showed a significant downward trend, decreased by 19.36% and 29.29% respectively; while the contents of high-density lipoprotein and free fatty acid showed a significant upward trend (P<0.05), increased by 60.38% and 23.65% respectively. Among the Coilia nasus samples from different stages of ovarian development in Anqing section, the triglyceride contents of stage IV samples was significantly different from that of stage II and stage III samples (P<0.05), increased by 67.24% and 53.75% respectively, and other indexes had no significant difference among the samples from different stages (P> 0.05).In summary, from Chongming to Zhenjiang, the serum triglyceride, high density lipoprotein and free fatty acid of Coilia nasus showed significant changes (P<0.05), which indicated that the lipid metabolism of Coilia nasus was active in the early stage of migration, and fat should be the main energy source for its migration and development.From Zhenjiang to Anqing, the metabolic level gradually adapted to the energy requirements of migration and gonadal development, so the serum energy index of Coilia nasus tended to be stable in the later stage of migration.