We examined the diet of pelagic juveniles of Trachurus japonicus in the surface layer in April, and subsequent demersal juveniles in the near bottom layer during May to June of the East China Sea (ECS) in 2005, 2008 and 2009. Diet composition of the pelagic juveniles showed a significant difference between 2005 and the other two years. That is, they preyed mainly on Paracalanus parvus s.l. and occasionally on Calanus sinicus in 2008 and 2009, while they fed mainly on Corycaeus affinis in 2005, partly corresponding with the between-year difference in prey densities. The demersal juveniles depended heavily on the fifth copepodites and females of C. sinicus which store lipids in the body, i.e. high-energy food for the juveniles, without a significant inter-annual difference. The markedly low occurrence of P. parvus s.l. and C. sinicus, which are considered to be energetically more favourable than C. affinis, from the stomach of the pelagic juveniles in 2005 corresponded with the lowest growth rates of the pelagic juveniles in the three years. Potentially, this resulted in the lowest observed recruitment level of the demersal juveniles for the ECS in 2005 over these three years.