Abstract: Ecological and traditional theoretical biology experiments were conducted to study the allometric growth of larval and juvenile crimson snapper Lutjanus erythopterus at their early life stage to provide fundamental data in artificial propagation of crimson snapper. The 17th day post hatch of fish was the joint between the larval and juvenile crimson snapper. The results indicated that during the larval and juvenile stage, organs associated to feeling, breathing, feeding and swimming developed and differentiated rapidly with allometric patterns. As for head organs, rostrum length, mouth width, eye diameter and head region height exhibited positive allometric growth in larval stage. Rostrum length appeared isometric growth in juvenile stage of crimson snapper. Mouth width, eye diameter and head region appeared negative allometric growth. As for body region organs, head region length and body height exhibited positive allometric growth in larval stage. Torso region length and tail region length exhibited negative allometric growth. In juvenile stage, body height and torso region length showed positive allometric growth. Head region length and tail region length displayed isometric growth. As for swimming organs, dorsal fin, pelvic fin and caudal fin exhibited positive allometric growth and pectoral fin appeared isometric growth in larval stage. In juvenile stage, pelvic fin, pectoral fin and caudal fin appeared isometric growth, and dorsal fin showed negative allometric growth. The fast development of key organs of crimson snapper with efficient and low energy expenditure increases larval survival ability at the early stage in the short window, which, has important ecological significance to adapt the complex external environment.