Jellyfish are sometimes considered as valueless because of their supposed low nutritive content. Here, we conducted feeding experiments on silver pomfret juveniles to evaluate the dietary value of jellyfish. Six treatments, including a starvation treatment (S) and five feeding treatments, with Aurelia aurita (AA), Rhopilemaesculentum (RE), artificial diet (AD), both A. aurita and artificial diet (A&A), and both R.esculentum and artificial diet (R&A), were carried out to compare fish survival rates and growth performance. Fish with S treatment showed a 48% mortality rate and reduced body weight, whereas fish with AA and RE treatments showed no death and much increased body weight. Fish with A&A and R&A treatments exhibited a much faster growth than that with AD treatment. Further, the effects of diet on biochemical composition of silver pomfrets were explored. Monounsaturated fatty acid (MUFA), seven different fatty acids, and six different essential amino acids (EAAs) were showed to be good indicators to assess silver pomfrets’ response to their prey. Our experiment indicated that the jellyfish, A. aurita and R.esculentum, can provide energy for silver pomfrets’ metabolism and growth, and as supplemental food are suitable for rearing silver pomfret juveniles.