This study investigated morphological structure and growth characteristics of juvenile Asian arowana,Scleropages formosus listed in CITES as a highly endangered fish species,which is an ancient member of the Osteoglossidae family inhabiting Southeast Asia.The result showed(1) body compressed and elongated,with pelvic scutes,snout pointed sharply,mouth superior and slit slanted,chin barbells 1 pairs,cycloid scales very large on body,scale formula 23-25;dorsal fin 18-19,pelvic fin 1+4,anal fin 25-26,pectoral fin1+6,caudal fin 15.End of the tongue roundness,dissociation,with cartilage;5 gill archs,15-17 gill rakers; stomach with “U”shape winding is big and thick wall,2 pyloric caecum;left liver bigger than right liver;1 swim bladder,almost as long as abdominal cavity;1 gonad,mature females have about 30-60 mature eggs,egg diameter up to 12-15 mm.(2) The general correlation equation of body length(AL)and body weight(W)was W=0.023 5L^{2.876 3}(R²=0.986 7)under artificial farming conditions,which indicated the growth trend of body length and body weight was almost synchrony.(3) Body length of juvenile Asian arowana grew relatively slowly before five-month-old but subsequently accelerated growth.The relation with body length and monthold presented linear,namely AL=-0.007 7m³+0.161 5m²+1.363 3m+6.688 3(R²=0.998 7).Then the linear correlation equations between body weight that rapidly put on weight at juvenile stage and month-old was W=-0.133 6m³+5.554 5m²-6.915m+9.911 6(R²=0.997 2).The value for daily weight gain varied with different periods of growth,and the growth maximum of daily weight gain was 3.06 g/d at twelve-month-old.(4) And fatness of juvenile Asian arowana usually varied with the month age.