An 18-week growth trial was conducted in flow-through aquarium system to evaluate the practical dietary protein sources for juvenile abalone (Haliotis discus hannai). Three replicate groups of the abalone averaging 0.11g were fed one of ten diets containing casein, white fish meal (WFM), meat meal (MM), feather meal (FM), blood meal (BM), soybean meal (SM), corn gluten meal (CGM), cotton seed meal (CSM), Undaria powder (UP), or wheat flour (WF) as a dietary protein source. In addition, these dietary protein sources were cmpared with algae such as raw Undaria or dried Laminaria. Weight gain of abalone fed the diets containing casein, WFM, SM, CSM, or UP was significantly higher (P<0.05) than those of abalone fed other diets, and this value of abalone fed FM, BM, CGM, or algae was lower than other groups. Shell length, shell width, body wt./shell length ratio, and body wt./shell width ratio of abalone fed casein, WFM, SM, CSM, UP, and WF were also highe (P<0.05) than those of other groups. There were no significant difference (P>0.05) in moisture and protein contents of soft body among all diets. The data obtained in this study indicate that each of the casein, WFM, SM, CSM or UP is good dietary protein source for juvenile abalone.